BENIGNI I MALIGNI TUMORI BUBREGA

SVE O WILMS TUMORU - NEFROBLASTOM

EPIDEMIOLOGIJA -most common malignant abdominal tumor among children, - more than 70% of pediatric renal masses -87% of pediatric renal masses and occurs in approximately 1:10,000 persons -manifests between 6 months and 5 years of age -PEAK - 3-4 years of age, and 80% of patients present before 5 years of age -overall survival rate exceeds 85% -survival is impaired in those with an unfavorable histologic subtype or synchronous bilateral Wilms tumors -Wilms tumor is more commonly associated with intralobar rests than with perilobar rests -bilateral in 4%-13% of children MALFORMACIJE S KOJIMA JE WT UDRUŽEN -cryptorchidism (2.8% of cases) -hemihypertrophy (2.5%) -hypospadias (1.8%) -sporadic aniridia SINDROMI S KOJIMA JE WT UDRUŽEN -WAGR syndrome (Wilms tumor, aniridia, geni- tourinary abnormalities, mental retardation) -Drash syndrome (male pseudohermaphroditism, progressive glomerulonephritis) -Beckwith- Wiedemann syndrome or hemihypertrophy -Perlman syndrome (fetal gigantism with multiple congenital abnormalities) -Bloom syndrome -trisomy 18 -linear sebaceous nevus syndrome PATHOLOGY -occasionally largely cystic, in which case it may not be differentiated from cystic partially differentiated nephroblastoma, a subtype of multilocular cystic nephroma -anaplasia - presence of gigantic polyploid nuclei within the tumor sample / high resistance to chemotherapy / poor prognosis / manifest at a later age / more association with abdominal pain at the time of presentation / higher frequency of associated chromosomal abnormalities / ALI POSTOJI IZNIMKA - anaplasia does not necessarily indicate a grave prognosis, especially if it is focal and if diagnosed in stage I, and in fact this subgroup of patients can have an excellent prognosis IMAGING -vary depending on the amount of necrosis, hemorrhage, calcification, fat, and cystlike formation -well-defined solid mass with a pseudocapsule usually is seen -mass distorts renal parenchyma, leading to a rind or "claw" of renal tissue surrounding the tumor, a finding that helps distinguish Wilms tumor from neuroblastoma -Wilms tumor may invade the surrounding renal vein (the inferior vena cava), with possible ex- tension into the right atrium -bilateral in an estimated 6%-13% of affected children, and it is multifocal in one kidney in 12% of affected children -metastases - lungs, lymph nodes, liver, retroperitoneum --WT is occasionally largely cystic, in which case it may not be differentiated from cystic partially differentiated nephroblastoma, a subtype of multilocular cystic nephroma US -heterogeneous echogenicity, which represents hemorrhage, fat, necrosis, or calcification -examination of the inferior vena cava is critical to detect tumor extension, which could necessitate modification of the surgical approach CT -heterogeneous mass -nodal metastases - areas of calcification and fat -intravenous administration of contrast material is mandatory to detect nodal or hepatic metastases, tumor extension into the renal vein or inferior vena cava, contralateral synchronous tumor, and associated nephrogenic rests MR -hipoT1 i hiperT2-weighted images -assessment of caval patency and multifocal disease -often very large at presentation and can cause severe distortion of adjacent organs, including the inferior vena cava -most sensitive modality for determination of caval patency -CE - Wilms tumor demonstrates enhancement but to a lesser degree than that of normal renal parenchyma DIF.DG. -rhabdoid tumor -clear cell sarcoma -mesoblastic nephroma -multilocular cystic nephroma -pitanje je polazište tm - renalna ili suprarenalna loža --neuroblastom - puno češće ide s kalcif. / mlađa dob koju zahvaća za razliku od WT / okružuje žile ali ih ne invadira --feokromocitom --ACC THERAPY -stage 1 and stage 2 Wilms tumors are treated with nephrectomy and chemotherapy -abdominal radiation therapy is added for stage 3 and stage 4 disease -preoperative chemotherapy is performed in patients with stage 5 disease and in those with a large tumor -partial nephrectomy typically is not performed -bilat. Wilms tumor, preoperative chemotherapy is especially important because each kidney is staged separately, and complete resolution of dis- ease in one kidney may allow surgery on the contralateral kidney with eventual cure -in patients with bilateral Wilms tumor, the current approach is tumor resection with sparing of normal parenchyma

MIXED EPITHELIAL AND STROMAL TUMOR OF THE KIDNEY - MEST

1. KLINIČKO-EPIDEMIOLOŠKI PODACI -100 cases of MEST have been reported in the literature, with the tumor occurring almost exclusively in perimenopausal women -hematuria, flank pain, a palpable mass, or urinary tract infection 2. DEFINICIJA -MEST is a complex solid and cystic renal tumor with stromal and epithelial elements -stromal component consists of spindle cells that mimic ovarian stroma and that express estrogen and progesterone receptors -epithelial component contains epithelium-lined cysts or microcysts -almost all reported cases, MEST has behaved in a benign fashion following surgical resection BUT there have been a few reported cases of malignant sarcoma associated with MEST 3. IMAGING -well-circumscribed, multiseptate cystic and solid mass with delayed contrast material enhancement -heterogeneous hyperechoic mass at US -solid and cystic mass with heterogeneous enhancement at MR imaging -- the cystic region demonstrated T1 hypointensity and T2 hyperintensity, whereas the central nodular component demonstrated T1 hyperintensity, T2 hypointensity, and evidence of contrast enhancement 4. PRIKAZ SLUČAJEVA -expansile complex renal mass with heterogeneous and delayed contrast enhancement -classic multiloculated cystic appearance with a variable proportion of cystic and solid components -internal septa demonstrated variable contrast enhancement, and an enhancing mural nodule was identified in one case -two cases demonstrated focal mural calcifications -one case demonstrated focal hyperattenuating areas compatible with hemorrhage -RARE - tumor consisted of a predominantly fatty lesion with no appreciable cystic component at CT -MEST may also herniate into the renal pelvis and simulate a transitional cell carcinoma 5. DIFERENCIJALNA DG. A. MEST vs. ACN (adultni cistični nefrom) -MEST and ACN may represent different parts of the morphologic spectrum of the same disease -share many clinical and pathologic features -both have female predilection and predominantly affect perimenopausal women, -at CT both appear as a complex cystic lesion with thin septa -both may herniate into the renal pelvis, resulting in hemorrhage or urinary obstruction B. MEST vs. cystic RCC -most MESTs represent Bosniak category III or IV lesions --> a cystic RCC is an important consideration in the differential diagnosis -cystic change occurs in up to 15% of RCCs -spectrum of cystic RCC includes multilocular cystic RCC, RCC arising from a preexisting be- nign cyst, and cystic degeneration of a previously solid RCC -compared with MEST, cystic RCC tends to have thicker, irregularly enhancing septa and enhancing nodular or solid components C. MEST vs. COMPLEX CYST -complex renal cyst is also part of the spectrum of cystic renal lesions - containig thin, nonenhancing internal septa with thin mural calcifications and no mural nodularity D. MEST vs. MDK (multicystic dysplastic kidney) or DUPLICATED RENAL COLLECTING SYSTEM or ABSCESS -MEST may also mimic MDK or an obstructed -MDK demonstrates replacement of normal renal parenchyma with variable-sized cysts that do not interconnect but with minimal or no contrast enhancement, and no contrast material excretion is seen during the excretory phase (Fig -duplicated renal collecting system with obstructed upper pole calices, a finding that may simulate a cystic renal lesion -MEST may also simulate a renal abscess which are thick, irregularly enhancing wall with infiltration of the perirenal fat

PREPORUČENI FOLLOW-UP PACIJENATA S RCC-om

--for T1 and T2 tumors, annual chest X-rays are performed; with 6 monthly chest X-rays for 3 years --CT of the abdomen is performed at 6, 12, 24 and 36 months for T3 and T4 tumors 1. FOLLOW-UP OF PATIENTS UNDERGOING ACTIVE SURVEILLANCE --this is an evolving area, but active surveillance has been recently recommended as suitable for stage T1N0M0 renal masses in selected patients by the American Urologic Association --rapid growth or size larger than 4 cm are triggers for treatment --abdominal imaging (CT, MRI, or ultrasound) was performed at 3 and 6 months, then every 6 months until year 3, and then annually thereafter --tumor doubling time as a measure of aggressiveness has not yet been defined, and neither have morphologic alterations 2. FOLLOW-UP FOR PATIENTS WITH RENAL TUMOR SYNDROMES --in the familial sy conventional cyst classification (i.e., the Bosniak classification) is not applicable because all the cysts, however innocuous looking, require radiologic follow-up --likelihood of metastases is low if the solid component of a cyst is smaller than 3 cm --> surveillance is performed until any given cyst develops a solid mass larger than 3 cm, at which stage treatment is triggered --high risk: CT or MRI scan every 3-6 months --low risk: should be imaged every 2-3 years 3. FOLLOW-UP FOR METASTATIC RCC UNDERGOING CHEMOTHERAPY --10% or more decrease in tumor size or a 15% or more decrease in tumor density on contrast-enhanced CT are signs of partial disease response --20% or more decrease in size and internal tumor density of 40 HU or less are better thresholds for assessing response --marked central necrosis is a favorable sign after treatment --new metastasis or nodular areas of enhancement within a non-enhancing mass are signs of disease relapse --contrast-enhanced CT of thorax, abdomen, and pelvis 3 months after treatment commences and every 3 months thereafter --additional imaging (e.g., directed at the brain or the bones) is reserved for patients with symptoms 4. FOLLOW-UP AFTER THERMAL ABLATIVE THERAPY --cryotherapy and radiofrequency ablation are now established treatment options for stage T1aN0M0 --3% and 21% of tumors have required repeat treatment, and this is more likely in tumors larger than 4 cm in diameter --timing of the first scan after treatment is variable among reported studies (from im- mediately after ablation to up to 1 month after treatment) --early scanning is important, because the majority of inadequate treatments were noted within 3 months of ablation in one study --abdominal CT has been suggested at 1, 3, 6, and 12 months --abnormal enhancement is a key indicator of residual or recurrent local disease --after effective ablation, the tumor is seen as an area of increased density (> 40 HU) on the unenhanced studies with a surrounding rim of fat (so-called "bull' s-eye" appearance), particularly with exophytic masses --dense central zone represents the successfully ablated tumor as well as a penumbra of devitalized renal parenchyma around the tumor included as a treatment margin --bull's-eye appearance is also seen on MRI, with heterogeneous increased T1 signal and de- creased T2 signal of the ablated area --rim of variable signal intensity is also seen on both T1- and T2-weighted images with interposed fat --change in size is not a reliable indicator of treatment adequacy. In one study, mean tumor volume was larger soon after ablation (within 1-2 months), and reduction in size was not seen until 12 months had elapsed --successfully ablated tumor will decrease in size (by up to 75% after cryoablation) but complete disappearance is seen in only a minority of cases --rim enhancement is not rare after ablative therapy - this can be problematic, because residual tumor is also more likely at the periphery -benign rim enhancement has a smooth margin, whereas residual tumor shows heterogeneous enhancement --most reliable sign of tumor relapse is an enlarging nodular or crescentic area that shows unequivocal enhancement --increase of 20 HU or more after contrast medium administration is highly suspicious for residual tumor, and repeat ablation may be required --an increase of 10 HU or less is compatible with successful ablation --intermediate increase of 10-20 HU is considered equivocal --length of follow-up necessary is also undefined, although 5 years has been suggested 5. FOLLOW-UP AFTER NEPHRECTOMY --patients who have undergone partial nephrectomy with positive surgical margins are at a greater risk of local recurrence, and after either type of nephrectomy, there is a risk of distant metastases, which is more likely with higher tumor grades --enlarging area of abnormal renal enhancement at the surgical site is suspicious for residual cancer --after total nephrectomy, an enlarging mass in the surgical bed, with or without a necrotic center, is also a sign of recurrence, but this is an infrequent occurrence (< 3%) --care should be taken not to mistake prolapsed bowel loops or pancreatic tail in the nephrectomy bed as a sign of recurrent tumor --has been suggested that the abdomen should be scanned in the early arterial phase and in the portal venous or nephrographic phase to improve detection -in one recent study of patients with RCC metastases in the liver or pancreas, 9% were seen in the arterial phase only, and 6% were detected in the portal venous study

RCC VS nonRCC NA IMAGING-u

--increase in attenuation of 84 HU in the corticomedullary phase differentiates clear cell RCC from non-clear cell tumors with a sensitivity of 74% and a specificity of 100%

INDIKACIJE ZA PARCIJALNU NEFREKTOMIJU

--tumor < 4 cm --LOCATION: polar, cortical, and far from the renal hilum and collecting system --peripheral location --absence of the contralateral kidney --bilateral renal tumors --renal insufficiency --risk of future impairment of renal function from another condition or a risk of bilateral renal tumors --Nephron-sparing surgery entails complete excision of the renal tumor with a margin of at least 0.5 cm of normal renal tissue and preservation of the largest amount of functioning renal parenchyma.

SINDROMI VEZANI UZ RCC + RIZIČNI FAKTORI

-2-4% of RCC having a hereditary cause -they include: --von Hippel-Lindau (VHL) syndrome --hereditary papillary RCC --hereditary leiomyomatosis RCC --Birt-Hogg- Dube syndrome --chromosome 3 translocation --tuberous sclerosis (TSC1, TSC2) RF: --long-term dialysis carries (3-6x veći rizik) --tobacco is the most significant risk factor --diuretic use --obesity (particularly in women) --hypertension --unopposed estrogen therapy --exposure to asbestos --petroleum products, and heavy metals --chronic renal failure --acquired cystic disease - pRCC je često vezan uz ovaj entitet --HIV --transplantation

RADIKALNA NEFREKTOMIJA

-KIDNEY + includes excision of the perirenal fat, including the ipsilateral adrenal gland, and a lymph node dissection of the region from the diaphragmatic crus to the aortic bifurcation of the ipsilateral—and possibly the contralateral aspects of the IVC or the aorta -accuracy for the detection of perinephric extension of disease by high-resolution CT have been reported to be 93-96%

SVE O ONKOCITOMU

-approximately 3-7 % of all renal tumours -originate from or differentiate toward type A intercalated cells of the cortical collecting duct -peak age of incidence is in the seventh decade; men are more likely to be affected than women -typical imaging findings of renal oncocytoma are described as a homogeneous HYPERVASCULAR mass with subsequent washout in the delayed phase - CENTRAL SCAR is a characteristic finding, especially in a large oncocytoma JAKO BITNO SEGMENTAL ENHANCEMENT INVERSION is a term defined as a renal lesion that has two distinct zones of enhancement which shows inverse patterns between the -corticomedullary (30-40 s) and -early excretory (120-180 s) phases 1. one zone is hyperenhancing on the corticomedullary phase, which subsequently becomes hypo-enhancing on the early excretory phase 2. other zone is hypoenhancing on the corticomedullary phase and becomes hyperenhancing on the early excretory phase BUT - several studies examining the discrimination of RCC from oncocytoma based on the corticomedullary phase have shown inconsistent results NEKI SU POKAZALI DA JE TO KARAKTERISTIKA ONKOCITOMA, NEKI SU POKAZALI DA NIJE. VARIOUS IMAGING FINDINGS GLAVNI PROBLEMI -discrimination of oncocytoma from RCC be challenging -the presence of oncocytoma with concurrent RCC may be a diagnostic problem UZORCI IMBIBICIJE ONKOCITOMA POSTULAT 1. -oncocytomas demonstrated greater enhancement than clear cell RCC in the corticomedullary phase -clear cell RCC demonstrated greater enhancement than oncocytoma POSTULAT 2. -peak enhancement of clear cell RCC was seen predominantly in the corticomedullary phase, while that of oncocytoma was seen predominantly in the nephrographic phase POSTULAT 3. -oncocytoma commonly showed avid enhancement in the venous phase POSTULAT 4. -oncocytoma may present as a hypovascular mass with gradual contrast enhancement or a persistently hypovascular or cystic mass POSTULAT 5. -in oncocytoma, the degree of tumoural enhancement and the timing of peak enhancement are variable POSTULAT 6. -segmental enhancement inversion based on the corticomedullary and early excretory phases was a characteristic enhancement pattern of a relatively small (<4 cm) oncocytoma POSTULAT 7. -some of the studies didnt find segmental enhancement inversion in oncocytoma or RCC POSTULAT 8. -enhancement pattern of RCC (clear cell RCC or chromophobe RCC) may mimic segmental enhancement inversion POSTULAT 9. - most common feature of oncocytoma (<4 cm) was a heterogeneous enhancing mass that became homogeneous on the delayed phase POSTULAT 10. -when segmental enhancement inversion was inconspicuous in the early excretory phase, oncocytomas might appear nearly homogeneous, especially in the case of small oncocytomas - similar finding may be seen in RCC CHARACTERISTIC ENHANCEMENT PATTERN FOR RENAL ONCOCYTOMAS HAS NOT BEEN WIDELY ACCEPTED!!! ZAKLJUČAK: -vascularity and enhancement patterns of oncocytomas are various, and oncocytomas can present as an either homogeneous or heterogeneous mass -when an oncocytoma presents as a heterogeneous hypervascular mass, it may mimic clear cell RCC -when an oncocytoma presents as a homogeneous hypovascular mass, it may mimic chromophobe or papillary RCCs on CT RADIOLOGICAL-PATHOLOGICAL CORRELATION OF RENAL ONCOCYTOMA -three cellular patterns of renal oncocytomas: --organoid - MOŽE BITI VISOKA ILI NISKA CELULARNOST ---organoid pattern is characterised by nests of tumour cells surrounded by a reticular framework of thin blood vessels and stroma ---tumour nests can be tightly packed (high cellularity) or loosely arranged within an oedematous stroma (low cellularity) --tubulocystic - NISKA CELULARNOST ---characterised by tumour cells arranged as tubular and cystic structures separated within an oedematous stroma (low cellularity) --mixed pattern IMBIBICIJA OVISNA O HISTOLOGIJI 1. High cellularity (organoid pattern) - intense arterial enhancement and subsequent washout 2. Two distinct areas of high cellularity and low cellularity (oedematous stroma) components - segmental enhancement inversion 3. Mixture of organoid pattern with rich vascularity and oedematous stroma - arterial enhancement that persists in the nephrographic phase 4. Abundant oedematous stroma (low cellularity) - hypovascularity and gradual enhancement 5. Cystic and/or haemorrhagic change - hypoehancement in the corticomedullary and delayed phase --- 5 % to 20 % slučajeva IZGLED ONKOCITOMA NA MR-u -high cellular component - moderate signal on T2- weighted images + high signal on diffusion-weighted imaging -high T2 signal within the tumour may reflect oedematous stroma, central scar or cystic change -dynamic contrast-enhanced MRI findings are similar to CT --components of high cellularity demonstrate arterial enhancement --component of high T2 signal shows gradual enhancement with partial or complete fill-in -apparent diffusion coefficients (ADCs) of oncocytomas were significantly higher than that of RCC -it is questionable whether DWI is useful in the differential diagnosis of oncocytoma versus RCC due to the variability of oncocytoma cellularity NEOBIČNI NALAZI ONKOCITOMA NA IMAGINGU 1. kalcifikati - nije čest / typically present within the central scar 2. multifokalni onkocitom -max 16 % of cases -bilateral max 12 % -can be either sporadic or associated with Birt-Hogg-Dube syndrome (rare; AD; cutaneous hair follicle tumours; multiple renal tumours - RCC and oncocytoma; renal and pulmonary cysts) -presence of pulmonary cysts helps to discriminate Birt-Hogg-Dube syndrome from von-Hippel Lindau disease -pojam renalna onkocitoza --diffuse replacement of the renal parenchyma by numerous oncocytic tumours, such as hybrid tumours, chromophobe RCCs, renal oncocytomas, and oncocytic renal parenchyma --may occur sporadically or may be associated with chronic renal failure and long-term haemodialysis 3. onkocitom sinkron s RCC-om -incidence is up to 10 % -hybrid tumour or as a separate mass in the ipsilateral or contralateral kidney -renal oncocytomas and chromophobe RCC may be related entities (oncocytic lesions) -these tumours may arise from a common precursor with the potential to differentiate into either a benign (oncocytoma) or malignant (chromophobe RCC) lesion NEKE PROMJENE U KONTROLNOM INTERVALU MOGU NAS NAVESTI DA ZA ONKOCITOM POSUMNJAMO DA JE MALIGNI 1. INTERVAL GROWTH -reported mean growth rate of clear cell RCC (0.7 cm/year) is not significantly different from that of oncocytomas (0.5 cm/ year) 2. EXTENSION TO THE PERINEPHRIC FAT -atipična karakteristika onkocitoma -oncocytomas typically present as a well-circumscribed or lobulated mass and associated perinephric fat extension is typically radiologically subtle 3. ONCOCYTOMA ARISING IN END-STAGE RENAL DISEASE -preoperative diagnosis of oncocytoma is difficult and the association between renal cell carcinoma and long standing dialysis is well-known, surgical treatment is warranted if the tumour is resectable

LIPOMATOUS HEMANGIOPERICYTOMA

-as solid fat-containing mass arising from the deep soft tissues of the thigh and retroperitoneum -it has not been reported in the visceral organs previously, except for one case affecting the kidney -they appear as well-demarcated, heterogeneously enhancing lesions -fat component, if present, can be detected on CT and MRI -differentiation of the lesion from macroscopic fat-containing angiomyolipomas may be difficult or impossible

TUBEROZNA SKLEROZA (Bourneville disease)

-autosomal dominant disease -tumors in multiple organs, including the brain, lungs, skin, liver, and kidneys -70-90% of individuals with TSC have renal angiomyolipoma by adulthood -simple cysts are another common renal manifestation -phacomatosis -the triad of adenoma sebaceum, seizures, and mental retardation -autosomal dominant; however, spontaneous mutation occurs in 56%-80% of individuals with tuberous sclerosis --facial angiofibroma (adenoma sebaceum) or forehead plaque --nontraumatic ungual or periungual fibroma --hypomelanotic macules (three or more) --shagreen patch (connective tissue nevus) --multiple retinal nodular hamartomas --cortical tuber --subependymal nodule --subependymal giant cell astrocytoma --cardiac rhabdomyoma (single or multiple) --lymphangiomyomatosis --renal angiomyolipoma -Less specific features --multiple randomly distributed pits in dental enamel --hamartomatous rectal polyps --bone cysts --cerebral white matter radial migrational lines, --gingival fibromas --nonrenal hamartoma --retinal achromic patch --"confetti" skin lesions --multiple renal cysts

KLINIČKA SLIKA RCC-a

-classic clinical presentation of flank pain, hematuria, and a palpable flank mass is comparatively uncommon (5-10% of cases). -clinical symptomatology may be quite nonspecific—for example, anorexia, tiredness, weight loss, or fever of unknown origin - varicocele formation (from tumor thrombus in the left renal vein or the inferior vena cava [IVC]) and disseminated malignancy -variety of paraneoplastic syndromes, such as polycythemia secondary to excessive secretion of erythropoietin, hypercalcemia secondary to factors regulating calcium, and hepatic dysfunction (Stauffer syndrome)

EXTRAMEDULLARY HEMATOPOESIS

-most commonly seen in myelofibrosis -it may also be seen in patients with thalassemia, hereditary spherocytosis, and sickle cell disease -most commonly detected in the reticuloendothelial system, i.e., the liver, spleen and lymph nodes, although it has also been described in the pleura, pericardium, adrenal glands, spinal cord, breast, thyroid, and kidney -extramedullary hematopoiesis is well-known in the kidney, presentation with large renal lesions is extremely rare, around ten case reports to our knowledge -CT may reveal lobulated masses with mild homogenous enhancement and pelvicalyceal areas are commonly involved -despite engulfment of the kidneys by the mass, the kidney shape is commonly preserved -masses commonly appear as T2-hypointense on MRI

INFLAMMATORY MYOFIBROBLASTIC TUMOR

-rare benign disease of the kidney which is characterized with mass forming proliferation of myofibro- blasts, fibroblasts, histiocytes, and plasma cells in the affected portion of the kidney -mimics renal malignancy on imaging studies with appearance of heterogeneous mass and contrast enhancement -diagnosis of IMT usually depends on suspicion of a benign condition with clinical and imaging findings of a renal mass -follow-up imaging studies reveal regression of such lesions -hypoechoic heterogeneous mass on US -CT reveals ill-defined, hypovascular, homogeneous renal mass. -hypointense appearance on both T1- and T2-weighted MRI

KOME DATI antiVEGF TERAPIJU?

-routine screening for VHL mutations in all patients with clear cell RCC is not recommended because the predictive role of the VHL mutation in determining prognosis of RCC has not yet been established -there is genet- ic overlap between various RCC subtypes that can lead to unexpected response patterns -no other better therapeutic options are available at present for patients without inactivation of the VHL gene -it is reasonable to give all the patients a trial of antiangiogenic agents with the understanding that those without the mutation may show limited response

RENAL SCHWANNOMA

-schwannomas of the kidney are extremely rare neoplasms -around 20 patients have been reported in the literature -mostly located in the renal hilum, like our case, abutting or compressing the hilum and renal pelvis -MRI signal characteristics of the lesion were similar to schwannomas detected elsewhere, hypointense on T1 and hyperintense on T2 with an avid enhancement after intravenous gadolinium injection -but in our patient the mass did not show intense contrast enhancement on CT

PAPILARNI ADENOM

-the most common renal epithelial neoplasms -40% of patients older than 70 years harbor renal adenomas -commonly found in patients with acquired renal cystic disease and in patients undergoing long-term hemodialysis -papillary adenoma-to- carcinoma sequence has been described that is akin to similar transformation in colonic adenomas -papillary adenomas are extremely small (< 5 mm) and may not be distinguished from other renal tumors (particularly RCC) and pseudotumors on imaging studies -subcapsular and solitary -histologic and genetic abnormalities of renal adenomas are indistinguishable from papillary RCCs

UNUSUAL IMAGING MANIFESTATIONS OF RCC

1. BILATERAL SYNCHRONOUS MULTIFOCAL RCCs -4% slučajeva -von Hippel-Lindau disease, hereditary papillary RCC -clear cell or papillary subtype -multifocality is defined as the presence of more than one ipsilateral or contralateral RCC of the same histologic subtype -prevalence of multifocality is greater in patients with bilateral synchronous RCCs 2. SYNCHRONOUS ADRENAL METASTASIS FROM RCC -risk of synchronous ipsilateral adrenal involvement from RCC ranges from 1% to 7% -multifocality, vascular invasion, and the presence of distant metastases are independent variables predictive of adrenal metastasis -synchronous contralateral adrenal involvement is even more unusual 3. RCC ASSOCIATED WITH BULKY ABDOMINAL LYMPHOMA -higher than expected concurrence of RCC with non-Hodgkin lymphoma -knowledge of this association is essential to avoid misdiagnosis as lymph node metastases from an RCC or as lymphomatous renal involvement 4. MULTISEPTATED CYSTIC CARCINOMA -complex cystic lesions manifesting with an increased number of septa or with minimal thickening of the septa or cyst wall are referred to as category IIF lesions (F stands for "follow-up") -follow-up CT will reveal that the great majority (95%) of these lesions are benign -lesions containing thicker or irregular septa are considered category III lesions -multiloculated renal cysts with three or more septa (categories IIF and III) grow more rapidly than simple cysts -rarely, cystic RCC may eventually manifest as a moderately complex renal cyst (multiseptated or cystic Bosniak category IIF lesion) at ultrasonography (US) 5. PARAAORTIC METASTATIC ADENOPATHY FROM AN UNDETECTED RCC -initial lymphatic metastases from an RCC usually occur in the paraaortic and paracaval regional lymph nodes, both above and below the renal vessels -presence of nodal metastases without radiologic evidence of a renal tumor is very rare -primary neoplasm was ra- diologically evident 6 and 36 months, respec- tively, after initial imaging work-up 6. RCC CAUSING A LARGE ARTERIOVENOUS FISTULA -arteriovenous communications from neovascularization may lead to early enhancement of the renal vein and inferior vena cava -solid components of the tumor may be hidden by the vascular communication -affected patients usually present with cardiac failure, an abdominal bruit, or renal hypertension, gross hematuria, and extrinsic indentation caused by collateral vessels in the upper portion of the left ureter 7. SPONTANEOUS PERIRENAL HEMATOMA -AML>RCC -AML > 4cm -- rizik za nastanak hematoma -za RCC veličina nije ključan faktor za rupturu jer su i manje mase od 4cm povezane s hemoragijom -angiography is particularly useful in cases of bilateral renal hemorrhage, since renal vasculitis (polyarteritis nodosa) is the most common cause of this condition -when the initial imaging examination does not demonstrate the cause of renal hemorrhage, repeat imaging following resolution or evacuation of the hematoma is essential -repeat imaging is important if unnecessary nephrectomy is to be avoided, although nephrectomy is performed in about 70% of patients 8. RCC ENGULFING PERIRENAL FAT -presence of fat in a renal lesion (from 20 to 120 HU on CT scans) is, for all practical purposes, diagnostic for AML and usually does not require follow-up or surgery (unless greater than 4 cm, in view of the risk of hemorrhage from larger AMLs -HOWEVER, sporadic cases of RCC with macroscopic evidence of fat have been reported MEHANIZMI NASTANKA 1. osseous metaplasia of the nonepithelial stromal portion of the tumor with growth of fatty marrow elements among the bone trabeculae / combination of fat and calcification should suggest the diagnosis of a malignant tumor because calcification is not usually present in AML 2. presence of cholesterol clefts and lipid vacuoles in areas of tumor lipid necrosis, as was recently seen in three patients with RCCs that contained intratumoral fat without evidence of calcifications at CT 3. the development of a distinct nodule of mature, well-circumscribed adipose tissue within an encapsulated, noncalcified papillary RCC 4. engulfment of perirenal or sinus fat by a large, exophytic and infiltrative tumor 9. TRANSPARENCHYMAL RENAL PROPAGATION OF RCC AND RENAL VEIN THROMBOSIS -transparenchymal renal propagation from a lower-pole RCC to the upper pole has not been described in the literature -propagation occurred through the renal cortex, sparing the medulla, but was associated with (a) invasion of the left renal vein and IVC and (b) extensive collateral venous circulation that caused notching of the left ureter

NEPHROBLASTOMATOSIS - DJECA

1. DEFINICIJA --diffuse or multifocal involvement of the kidneys with nephrogenic rests (NR) which are foci of metanephric blastema that persist beyond 36 weeks gestation and have the potential for malignant transformation into Wilms tumor 2. EPIDEMIOLOGIJA -1% of infants -nephrogenic rests (NR) give rise to approximately 30%-40% of Wilms tumors -nephrogenic rests (NR) are found in up to 99% of bilateral Wilms tumors 3. PH TIPOVI NR -dormant, sclerosing, hyperplastic, or neoplastic -dormant and sclerosing rests are usually microscopic and are not considered to have malignant potential -hyperplastic and neoplastic rests are grossly visible as small tan nodules surrounded by normal parenchyma 4. PODJELA NR PREMA LOKACIJI I UDRUŽENOSTI SA SY -perilobar and intralobar on the basis of location and the syndromes with which they are associated -but location and type of lesion may be definitely determined only with histopathologic analysis -perilobar rests lie in the peripheral cortex or columns of Bertin. They are associated with Beckwith-Wiedemann syndrome and hemihypertrophy, Perlman syndrome (visceromegaly, gigantism, cryptorchidism, polyhydramnios, characteristic facies), and trisomy 18. Malignant degeneration into Wilms tumor is most common in patients with Beckwith-Wiedemann syndrome and hemihypertrophy, occurring in 3% of cases -intralobar nephrogenic rests are considerably less common than the perilobar type but have a higher association with Wilms tumor development. These rests are found in 78% of patients with Drash syndrome and nearly 100% of patients with sporadic aniridia and are also seen in patients with WAGR syndrome. -range from well-demarcated to ill-defined nodules, depending on the subtype. -At CT, the nodules usually are hypo- to isoattenuating, and they demonstrate little or no enhancement compared with normal renal tissue -At ultrasonography (US), the renal shape is distorted, and the nodules are hypo- to isoechoic; however, it may be difficult to appreciate these nodules as distinct abnormalities. -At MR imaging, the foci are hypo- to isointense on T1-weighted images and they demonstrate variable signal intensity with little or no enhancement on T2-weighted images. -The intralobar type is more irregular than the perilobar type, which is easier to identify at imaging. -At MR imaging, corticomedullary differentiation is absent, and the kidneys usually are enlarged with a peripheral, well-demarcated rind of tissue. -Nephroblastomatosis is more homogeneous than Wilms tumor at all imaging modalities. -The presence of a distinct developing or enlarging mass, especially a heterogeneous mass, is indicative of Wilms tumor Although most children with nephroblastomatosis do not develop Wilms tumor, it is associated with perilobar rests, and 4%-5% of patients with intralobar rests are at risk for development of Wilms tumor. Diffuse nephroblastomatosis is usually seen as reniform enlargement with a thick peripheral rind of tissue that may show striated enhancement (4). At US, the enlarged kidney may have diffusely decreased echogenicity. Lymphoma can mimic either appearance of nephroblastomatosis but is unusual in infants and young children. It is currently believed that approximately 30%-40% of Wilms tumors arise from nephrogenic rests, which are found in as many as 99% of patients with bilateral Wilms tumors SCREENING -Screening is recommended at 3-month inter- vals for children at high risk for Wilms tumor or with nephroblastomatosis. -MR imaging is the method of choice for follow up; however, some authors recommend alternating MR imaging and US to reduce both cost and the use of deep sedation or anesthesia. -US can demonstrate a round focal mass, a finding suggestive of Wilms tumor.

LIMFOMI BUBREGA

1. EPIDEMIOLOGIJA -kad se limfom proširi --> 2. najčešće sijelo zahvaćeno limfomom nakon hematopoetskog tkiva i RES-a -i tad je prevalencija zahvaćanja bubrega 3-8% 2. OBLICI LIMFOMA A. SEKUNDARNI LIMFOM -nHL > HL -non-Hodgkin lymphoma, typically B-cell type intermediate- and high-grade tumors or American Burkitt lymphoma -- more than one-half of cases, renal or perirenal spread is detected at initial presentation -involvement by Hodgkin disease is much less common, being seen in less than 1% of patients at presentation RF -imunokompromitirani -EBV -HIV - immunoblastic and Burkitt subtypes is at least 113- 165 times greater than in the general population -nakon transplantacije - highest during the 1st year following the procedure B. PRIMARNI LIMFOM -less than 1% of cases of extranodal lymphoma -B-cell non-Hodgkin lymphoma -middle aged or older -ETIOPATOGENEZA: --lymphatic-rich renal capsule or the perinephric fat and invade the parenchyma --it can arise from lymphocytes present in areas of chronic inflammation 3. KLINIČKA SLIKA -flank pain, -hematuria -nonspecific symptoms of fever -night sweats -ABZ - extensive lymphomatous infiltration of the renal parenchyma and compression of the normal tubules can lead to acute renal failure 4. MODALITETI -CT - identificira leziju, odnos prema bubrežnim strukturama, najuočljiviji u nefrografskoj fazi, ali i ekskretorna faza je bitna -MR -hipoT1 / hipo-isoT2 / CE - enhance less than the surrounding normal parenchyma but some lesions demonstrate progressive enhancement on delayed images -US - may be the first test requested in patients who present with renal insufficiency or flank pain; consequently, it is important to recognize the relatively subtle US abnormalities caused by lymphoma -PET-CT - more sensitive and specific than conventional anatomic imaging in detecting additional small tumor deposits 5. IMAGING PATTERNS A. MULTIPLE LESIONS (50%- 60%) -BL > UL -multiple parenchymal masses of variable size, typically 1- 4.5 cm in diameter -nativno - slightly higher attenuation -CE - hipovaskularne i homogene mase, osim ako nisu veće tada mogu biti heterogene -nefrografska faza je ključna - many lesions are small and affect the medullary portion of the kidneys, with relatively little cortical deformity -retroperitoneal adenopathy - GOTOVO UVIJEK -kalcifikati - rijetko -MR - hipoT1 / iso-hipoT2 / hipovask. -US - hipoehogeni i homogeni / doppler - hipovask -DIF.DG. - metastaze (D, Ž, M) / APNF / septič. emboli ili apsces / sinkroni tumori - razlika u imbibiciji -thickening of perirenal fascial planes and infiltration of perinephric fat can be present in both inflammatory processes and lymphoma B. SOLITARY LESION (10%-25%) -CE - little enhancement -low-attenuation areas - hipodenzna područja koja se ne imbibiraju - zone nekroze - naročito nakon kemoterapije -cystic appearance - highly unusual -US - hipo, ali ponekad može imati akustičko pojačanje i time imitira cistu (RCC je ehogeniji na UZV) -DIF.DG. - lako za ccRCC, ali teže za pRCC i crRCC C.DIRECT EXTENSION FROM RETROPERITONEAL ADENOPATHY (25%-30%) -large retroperitoneal masses are seen invading or displacing the adjacent kidney -hidronefroza zbog vanjske kompresije je česta u ovom obliku bolesti -okluzija ili tromboza RA ili RV zbog infiltracije - rijetka kod limfoma D.PERINEPHRIC DISEASE (10%) -perirenal spread from retroperitoneal or renal lymphoma is not uncommon, isolated perinephric lymphoma is unusual -homogeneous perinephric soft tissue compressing the normal parenchyma without causing significant impairment of renal function -thickening of the Gerota fascia or plaques and nodules in the perirenal space - u manje dramatičnim slučajevima -US - hipoehogeno područje oko bubrega -DIF.DG. - sarcoma arising from the renal capsule and metastases to the perinephric space, as well as benign conditions such as perinephric hematoma, retroperitoneal fibrosis, amyloidosis, and extramedullary hematopoiesis E.NEPHROMEGALY -without distortion of the normal shape of the kidneys results from diffuse infiltration of the renal interstitium by malignant lymphocytes -more common in Burkitt lymphoma - bilo u primarnom ili sekundarnom obliku -global renal enlargement -CE - heterogeneous enhancement -loss of the normal differential enhancement between the cortex and the medulla in the corticomedullary phase -renal parenchyma is replaced by poorly marginated low-attenuation lesions -collecting system - often encased and stretched rather than displaced -lymphoma infiltrates and destroys the renal parenchyma extensively and manifests as a large, nonfunctioning kidney -US - globular enlargement of the kidneys with heterogeneous echotexture of the parenchyma and loss of the normal echogenic appearance of the renal sinus fat -in some cases, the infiltrative process is unilateral or asymmetric -DIF.DG. - transitional cell carcinoma, collecting duct or medullary carcinoma of the kidneys, or severe pyelonephritis F. RENAL SINUS INVOLVEMENT -uncommon occurrence -normalni sinus je zamijenjen homogenom mekotkivnom masom -vascular encasement is common -ALI posljedična hidronefroza je blaga -US - hypoechoic mass infiltrating the renal sinus / may be difficult to differentiate from heterogeneous renal sinus fat -DIF.DG - TCC, Castelman d. 6. BIOPSIJA --ako je sumnja na limfom bubrega - obavezno učiniti biopsiju --> bitno radi daljnjeg onkološkog liječenja 7. RADIOLOGIC-PATHOLOGIC CORRELATION -renal lymphoma has a variety of imaging appearances depending on the pattern of tumor proliferation at histologic analysis -infiltrativan oblik rasta - nefromegalija -vise fokalni oblici - kao posljedica destrukcije parenhima nakupinom limfomskih stanica -small masses may coalesce and grow, thereby distorting the renal contour -combination pattern is not unusual 8.MIMICKS A. SOLITARNE LEZIJE -RCC tends to have a more heterogeneous appearance than renal lymphoma / vascular invasion is frequently seen with RCC and almost never with lymphoma -metastases from primary tumors such as lung cancer, breast cancer, or synchronous renal cell cancer often manifest as bilateral masses that are indistinguishable from multifocal lymphoma B. INFILTRATIVNE LEZIJE -TCC - most demonstrate expansile growth when they are confined to the renal collecting system; however, they can demonstrate an infiltrative growth pattern with parenchymal renal invasion -APNF, XPNF C. PERIRENAL INVOLVEMENT -direct extension from primary renal cell carcinoma or by metastasis from primary cancers of the lung or breast or from melanoma -urinomas, pancreatitis, and retroperitoneal fibrosis D. BULKY ADENOPATIJA -very large nodes can be seen with other tumors, most often metastatic adenocarcinoma from the prostate, colon, or an unknown primary site -adenocarcinoma nodes tend to be "hard" and obstruct the renal vasculature, whereas the "softer" lymphomatous nodes encase and surround the vasculature but do not typically result in occlusion -discrete nodes are often more apparent with metastatic adenocarcinoma, whereas lymphomatous nodes usually manifest as a homogeneous conglomerate mass

KORISNI TIPOVI O PAPILARNOM RCC-u

1. EPIDEMIOLOGIJA -second most frequent RCC subtype, accounting for approximately 13%-15% of all known RCC lesions -patients present in the third to eighth decades of life -male-to-female ratio ranges from 2:1 to 3.9:1. -although most pRCCs are unilateral, pRCC is the most common multifocal or bilateral renal tumor 2. OBITELJSKI SY POVEZANI S pRCC-om -hereditary leiomyomatosis and RCC syndrome, -occasionally Birt-Hogg-Dubé syndrome are associated with papillary renal cell cancers (BHD is more commonly associated with chromophobe RCC and oncocytomas) -pRCC shares its histologic characteristics with a benign entity called papillary adenoma 3. IMAGING -calcification is seen slightly more often in pRCC than in cRCC -solid or cystic masses -solid tumors can appear homogeneous and uniform or heterogeneous with areas of necrosis -pRCCs larger than 3 cm in diameter may be heterogeneous with areas of necrosis and hemorrhage -RAZLIKA PREMA KROMOFOBNOM RCC-u: --chromophobe RCCs tend to be homogeneous even when large -pRCC enhances to a lesser degree than does cRCC in all phases of postcontrast imaging -O ČEMU OVISI IMBIBICIJA TUMORA: --extrinsic factors are determined by the CT protocol used, including the type of contrast material, the quantity, and the rate and duration of injection --intrinsic factors such as the patient's weight, cardiac function, state of hydration, and renal function are more difficult to correct - pRCC frequently shows a pseudocapsule and frequently has low signal intensity on both T1- and T2-weighted images 4. STAGING -unlike in cRCC, where nodal involvement carries a poorer prognosis, pRCC with regional nodal metastases is not necessarily associated with a poorer prognosis -tumor extension into the inferior vena cava, the renal vein, or its branches (stage T3b and T3c) is relatively less common in pRCC (8.2% of cases) than in cRCC -pRCC has been noted to metastasize less frequently than cRCC -prevalence of visceral metastases is 5.7%-11% in pRCC and 11.9%- 26.9% in cRCC -lung is the commonest site of metastases in patients with pRCC, a result similar to that in cRCC -bone and the brain were other common sites of metastases. -it is common for metastatic lesions from pRCC to show enhancement characteristics similar to those of the primary tumor and be hypovascular

TIPS-RCC

1. EPIDEMIOLOŠKI PODACI -the seventh most common histological type of cancer in the Western world and have maintained an increasing prevalence -5.-7. desetljeće / median 66 god -incidence is two to three times higher in men and is slightly more common in blacks than in whites -1% to 3% of all malignant visceral neoplasms -40% of patients with RCC die because of the disease progression, thus this tumor is the most lethal malignant urological tumor -most RCCs are incidentally found at imaging investigations -85-90% svih tumora bubrega -RCC are usually solitary but may be multifocal (6-25%), with bilateral RCC occurring sometime in the course of life in 4% of patients 2. NAJČEŠĆI HISTOLOŠKI TIPOVI RCC-a a) clear cell renal cell carcinomas (ccRCC), b) papillary renal cell carcinomas (pRCC) c) chromophobe renal cell carcinomas (crRCC) These three subtypes together represent more than 90% of all RCCs. 3. SVE OSOBITOSTI CLEAR-CELL RCC-a -most common variant, representing between 70% and 75% of all RCCs -sporadic, and the remaining 5% are associated with hereditary syndromes (von Hippel-Lindau disease, tuberous sclerosis) -five-year survival of 50%-60% -originates from the proximal convoluted tubules epithelium (renal cortex) and presents a predominantly expansile growth pattern -clear cells because of their lipid- and glyco- gen-rich cytoplasmic content -multicentricity and bilaterality are rare (5%) in sporadic cases PSEUDOKAPSULA -related to compression of the adjacent renal parenchyma by the expanding tumor -although a fibrous capsule can occasionally be observed at pathologic analysis IMAGING A) CT -hypervascularized and heterogeneous lesions due to necrosis, hemorrhage, cysts and calcifications -necrosis is more common in larger lesions, generally with dimensions > 4 cm -intense contrast uptake in the corticomedullary phase (120-140 HU) and typical washout in the nephrographic phase (90-100 HU) -may also present a hypodense pseudocapsule in the corticomedullary phase at CT B) MRI -signal intensity similar to the one of the renal cortex at T1-weighted images -hypersignal at T2-weighted images -other finding observed in up to 60% of ccRCC is signal loss at out-of-phase image (the presence of intracellular lipid content) -psuedocapsule - hypodense at T1 and T2 -discontinuity of this pseudocapsule generally indicates a high-grade tumor - interruption of this pseudocapsule correlates with advanced stage (invasion of perirenal fat) and higher nuclear grade -MRI diffusion-weighted imaging has not been useful in the differentiation of RCC histologi- cal subtypes C) KVANTIFIKACIJA CE IMBIBICIJE -percentages of signal alteration in the three phases after contrast injection in relation to the pre-contrast phase: --ccRCC (230%, 250% and 227% for the corticomedullary, nephrographic and excretory phases, respectively) --pRCC (49%, 92% and 88% for the corticomedullary, nephrographic and excretory phases, respectively) --crRCC (98%, 183% and 159% corticomedullary, nephrographic and excretory phases, respectively) SUMA SUMARUM: ccRCC>crRCC>pRCC SIGNAL INTENSITY CHANGES ON CORTICOMEDULLARY PHASE IMAGES ARE THE MOST EFFECTIVE PARAMETER FOR DISTINGUISHING CLEAR CELL AND PAPILLARY RCC D) LOCAL INVASION -relatively common finding of these lesions is extension toward the perirenal fat, renal sinus fat and into the renal vein and inferior vena cava -in the presence of venous invasion, perirenal collateral venous circulation is commonly observed E) HEMATOGENE METASTAZE -relatively common in clear cell carcinomas and affect principally the lungs, liver and bones -lymph node metastases are described in up to 15% of cases -ccRCC carries a worse prognosis than the other two more common histological subtypes (pRCC and crRCC) 4. SVE OSOBITOSTI PAPILLARY RCC-a - the second most common histological RCC subtype, representing about 10% of cases in the several series in the literature -from the epithelium of the proximal convoluted tubules -psammoma bodies and edema are common in the papillary cores -type 1 (basophilic) pRCC presents a single layer of basophilic cells surrounding the basal membrane - associated with a better prognosis -type 2 (eosinophilic) presents with papillae covered by cells with abundant granular eosinophilic cytoplasm, with prominent nucleoli associated with areas of necrosis - worse prognosis; high-grade tumor, frequently associated with ganglial metastasis and, in some cases, with venous invasion -pRCCs tend to be solid, well defined, slow-growing lesions, bilateral (4%) and/or multifocal (22.5%), associated with acquired chronic renal disease IMAGING -more homogeneous than ccRCC and hypovascular as compared with the adjacent renal parenchyma A) CT -mean density ranging between 50-60 HU, and 65-75 HU in the nephrographic phase (progressive uptake) -Herts et al (23) have shown that the likelihood of papillary RCC is close to 50% when the tumor-to-aorta or tumor-to-kidney enhancement ratio is less than 0.25 -cystic papillary RCCs demonstrate peripheral soft-tissue mural nodules that may enhance after intravenous contrast material administration. B) MRI -peripheral lesions with intense hyposignal on T2-weighted images (intratumoral hemosiderin content or to their architectural arrangement) -compact tissue architecture and higher nuclear cytoplasmic ratio might be responsible for lower ADC values comparing to ccRCC RARELY -lesions > 4.0 cm in diameter may be heterogeneous due to the presence of necrosis, hemorrhage and calcification -rarely these tumors may present internal foci of macroscopic fat (interstitial macrophage with cholesterol) or even intracytoplasmic fat and, in this case, signal loss is also observed on the out of phase sequence at chemical shift imaging -may also present as neoplastic cystic lesions, generally with hemorrhagic content and hypovascular mural solid papillary projections KORTIKALNI / HOMOGENI UGLAVNOM / HIPOVASKULARNI / hipoT2 U ODNOSU NA KORTEKS 5. SVE OSOBITOSTI CHROMOPHOBE RCC-a -5% of all malignant renal epithelial tumors -most frequent in the sixth decade of life -best prognosis amongst RCCs - metastasis occurs in only 7% of cases -maybe a very close relationship between the chromophobe variant and oncocytomas - originated from collecting ducts intercalated cells and constitute common associated findings in cases of Birt-Hogg-Dubé syndrome IMAGING A) CT -hypovascular as compared with the renal cortex -moderate contrast uptake (80-100 HU in the corticomedullary phase at CT scan) -spoke wheel pattern of enhancement -Not rarely, however, crRCC may appear as a homogeneous and remarkably vascularized lesion in the corticomedullary phase (120-140 HU) B) MRI -light hyposignal or intermediate signal intensity at T2 -may present a central scar -necrosis may occur in the voluminous lesions -pseudocapsule -signal loss on out of phase images due to microscopic fat has been reported -spoke wheel pattern of enhancement -compact tissue architecture and dense cytoplasm may cause lower ADC values comparing to ccRCC -ALI --> nema razlike u ADC-u između pRCC-a i crRCC-a --It is important to note that findings of crRCC are indistinguishable from those of oncocytomas (benign tumors originated from intercalated type B cells of the cortical collecting ducts), which may also present a central scar --second most common hypovascular tumor after papillary RCC CENTRALNI OŽILJAK / HIPOVASKULARAN AND SPOKE-WHEEL PATTERN OF CE / hipo-isoT2 6. SVE OSOBITOSTI COLLECTING DUCT CARCINOMA (BELLINI DUCT CARCINOMA) RCC-a -less than 1% of all malignant kidney tumors -it is important to highlight the high aggressiveness of this lesion --> 30% of patients already present with metastasis at the diagnosis, and 60-70% of them die within a two-year period -male prevalence is observed, and in general such lesions show up after the fifth decade of life IMAGING -heterogeneous lesions with extremely variable signal intensity on T2- weighted sequences, depending on the amount of hemorrhage, necrosis, cystic component and calcification -originate in the medulla, implying a differential diagnosis with transitional cell carcinoma -larger lesions may invade the cortex -solid>complex cysts -hypovascular - tending to heterogeneous or peripheral contrast uptake -almost all tumors exhibit focal cortical extension, and some even exhibit perirenal ex- tension -tendency to display infiltrative patterns, preserving renal contour rather than an expansile growth --U MEDULI BUBREGA / HIPOVASKULARNI / HETEROGENI / VRLO LOŠA PROGNOZA / OKO 5. DESETLJEĆA 7. SVE OSOBITOSTI MULTILOCULAR CYSTIC RCC-a -1-4% of all RCCs, -prevalence in men (male/ female ratio 3:1) at mean age of 50 years IMAGING -multiseptated cystic lesion separated from the kidney by a fibrous capsule -excellent prognosis and can be completely cured -recurrence and metastasis have not been described -calcification in septa or in the pseudocapsule occurs in up to 20% of cases. -complex cysts, classified as II-F to IV categories according to the Bosniak system MRI -on T1 and T2, they frequently show hyperintensity, likely due to proteinaceous fluid or hemorrhage, or may display heterogenous signal intensity on both pulse sequences -blood products of different ages may create various signal intensities - CE - there is minimal internal, asymmetric septal, or wall enhancement 8. SVE OSOBITOSTI MEDULLARY CYSTIC RCC-a -an extremely aggressive tumor, originating in the distal nephrons, from the collecting duct cells -association with sickle cell disease and sickle cell trait -affect young patients at the second and third decades of their lives IMAGING -infiltrating lesions causing calyceal obstruction and dilatation -hypovascular lesion -frequently associated with locoregional adenopathy -hemorrhage and necrosis contribute to tumor heterogeneity -typically associated with caliectasis -hypointense on T2-weighted MR images likely due to the presence of by-products of hemorrhage and necrosis -typically hypovascular at catheter angiography HIPOVASKULARAN / ISTO IZ SABIRNIH KANALIĆA / MLAĐI - 2-3. DESET. / IDE U LČ / POVEZAN S ANEMIJOM SRPASTIH STANICA 9. SVE OSOBITOSTI MUCINOUS TUBULAR AND SPINDLE RCC-a -very rare renal tumor originates from distal convoluted tubule cells and collecting ducts -fourth and fifth decades of life -male-to-female ratio is 1:4 -low-grade neoplasm -tumor is composed of densely clustered cells intermingled with clear mucinous stroma and a well defined spindle cell component IMAGING -do not present any typical feature -tend to be homogeneous, with low signal in- tensity at T1 -intermediate to slightly hyperintense signal at T2 -some of these lesions may present with an irregular central scar -hypovascular in relation to the adjacent cortex HIPOVASKULARAN / CENTRALNI OŽILJAK / INDOLENTAN 10. SVE OSOBITOSTI RCC ASSOCIATED WITH CHROMOSOME'S SHORT ARM TRANSLOCATION -origin involves the TFE3 gene and 11 Xp11.2 chromosome's short arm translocation -children and young adults IMAGING -well delimited mass with pseudocapsule -resembles to pRCC -BUT - may appear as heterogeneous lesions, particularly the larger and hypervascular ones 11. SVE OSOBITOSTI RCC ASSOCIATED WITH NEUROBLASTOMA -few cases -uni- or bilateral -no predilection for gender -young patients at a mean age of 13 years IMAGING -well delimited, hypovascular lesion, generally with a more indolent behavior 12. SVE OSOBITOSTI UNCLASSIFIED RENAL CARCINOMAS -4% to 6% of the neoplasms cannot yet be histologically characterized with accuracy -some findings are useful to identify such lesions, as follows --presence of sarcomatoid component without any recognized epithelial elements --production of mucin --presence of mixed stromal and epithelial elements --non-recognized cell types IMAGING -MRI findings likely display a wide spectrum -may be solid with a cystic component -hyperintense on T1- and isointense on T2-weighted images -heterogenous enhancement and contain hemorrhage This category includes the histological RCC subtypes with worst prognosis. 13. INHIBITORI TIROZIN KINAZE -tyrosine kinase inhibitors "sunitinib" and "sorafenib" for clear cell RCC - "temsirolimus" for papillary RCC 14. MRI TEHNIKE BITNE U EVALUACIJI TUMORSKIH MASA BUBREGA A) Breathhold imaging --eliminates respiratory motion artifacts and improves registration for subtraction postprocessing --fast imaging technique and single-shot pulse sequences, are now widely available and very effective with suspended respiration --> allows dynamic contrast-en- hanced (DCE) MRI with or without fat suppression B) 3D gradient echo sequence --dynamic and volumetric imaging under breathhold --image postprocessing with multiplanar reformatting, maximum intensity projection, and volume rendering is often used to assess the relationship between the tumor and vascular system --subtraction is useful for maximum intensity projection, volume rendering, and determining the contrast enhancement of any mass high on T1 or tiny structures, such as the septa or mural components of a lesion --accumulation of the contrast agent in the tumor over time can be used to extract both qualitative and quantitative information regarding the functional integrity of tumor microvasculature C) Fat detection techniques --macroscopic fat is assessed using frequency-selective fat suppression techniques --microscopic fat, i.e., intracytoplasmic vacuoles containing lipids, is assessed using chemical shift imaging, which is available ONLY WITH GRADIENT-ECHO IMAGING D) Diffusion-weighted imaging (DWI) --provides quantification of the Brownian motion of water molecules in tissues, which depends on tissue organization, cellularity, the integrity of cell membranes, and extracellular space tortousity 15. KIRURŠKO ILI ONKOLOŠKO LIJEČENJE --size of the primary tumor and evidence of venous involvement (T3b or T3c) --adjacent organ invasion (T4) --nodal metastasis (N1) --distant metastatic disease THOSE are critical in determining the surgical plan or need for systemic therapy. 16. RECIDIV NAKON OPERACIJE --there is debate regarding the prognostic significance of renal sinus fat invasion versus perinephric fat invasion - grouped as T3a --perinephric fat invasion has been found to be a significant predictor of recurrence and cancer-specific survival from tumors larger than 7 cm (T2) 17. PLANIRANJE OPERACIJE A) vascular involvement in RCC is a predictor of perioperative morbidity and mortality B) Hallscheidt et al. compared MDCT and MRI for utility in estimating the extent of tumor thrombus and found that the rate of diagnosis of tumor thrombus with MRI was not significantly greater than that with MDCT (MDCT had 96% accuracy) C) KLASIFIKACIJA EKSTENZIJE TUMORSKOG TROMBA I KORELACIJA S OP. KOMPLIKACIJAMA ---extent of involvement has been defined with several criteria, including thrombus level: ----level 0, renal vein; ----level I, < 2 cm above renal vein; ----level II > 2 cm above renal vein but below hepatic veins; ----level III, at the hepatic veins but below the diaphragm; ----level IV, above the diaphragm In a review of outcome among patients undergoing nephrectomy with tumor thrombectomy at the Mayo Clinic, perioperative complication rates increased with tumor thrombus level (level 0, 12%; I, 18%; II, 20%; III, 26%; IV, 47%) Extension of renal cell carcinoma into the renal vein alone (stage T3b) occurs in approximately 23% of patients and does not adversely affect the prognosis Spread of the tumor into the inferior vena cava is found in 4%-10% of patients and is more common with right-sided lesions. Patients with extensive involvement of the inferior vena cava and with nodal or distant metastases have a relatively good prognosis, with 5-year survival of 32%- 64%, provided that the thrombus is intraluminal, does not invade the vessel wall, and can be entirely resected Venous extension is optimally shown during the corticomedullary phase of enhancement, when contrast enhancement in the renal vein is at its peak. ZNAKOVI ZAHVAĆANJA VENA --most specific sign of venous extension is the presence of a low-attenuation filling defect --abrupt change in the cali- ber of the renal vein and the presence of a clot within collateral veins are helpful ancillary signs --enlargement of the renal vein is not sufficient evidence by itself because it can be caused by increased blood flow within a hypervascular renal cell carcinoma or it can occur as a normal variant --heterogeneous enhancement of the thrombus with contrast material indicates neovascularity and thus tumoral thrombus -level of involvement of the inferior vena cava dictates the surgical approach D) another finding shown to be a significant prognostic factor is invasion of the IVC wall (rather than luminal infiltration) by RCC tumor thrombus ---risk of death among patients with RCC invading the renal vein ostium wall was six times as great as that among patients without such in- vasion ---preoperative MRI had 90% sensitivity in estimation of wall invasion, as did IVC anteroposterior diameter of 18 mm and mean largest renal vein ostium diameter of 14 mm ---MRI had 100% sensitivity, 89% specificity, and 92% accuracy in prediction of IVC wall invasion MOST RELIABLE SIGN FOR IVC WALL INVASION IN THIS STUDY WAS THE PRESENCE OF TUMOR ON EITHER SIDE OF THE IVC WALL (transmural extension) ---preoperative identification of venous wall invasion may assist in determining the extent of IVC resection and reconstruction, use of neo- adjuvant therapy, and identification of patients who can be treated without surgery ---approximately 23% of renal cell carcinomas invade the renal veins and 7% invade the inferior vena cava E) ZAHVAĆANJE LČ --lymph node metastases occur in about 15% of patients in the absence of other metastases --positive predictive value of the finding of nodes larger than 1 cm on preoperative images is only 42% --for patients with clinical N0M0 disease with low-risk primary tumors, lymphadenectomy is unnecessary and would result in understaging in 1% of cases --five high-risk features -- ZA METASTAZE U LČ ---tumor size larger than 10 cm ---grade 3 or 4 ---category pT3 or pT4 ---histologic tumor necrosis ---presence of a sarcomatoid component Patients with two or more of those features were more likely to have positive lymph nodes. --Those advocating lymphadenectomy in patients at higher risk believe that excision of pathologically node-positive disease in the absence of metastasis not only may improve staging but also may have therapeutic benefit. --STANDARD TEMPLATE FOR DISSECTION - nodes from the ipsilateral great vessel and the interaortocaval region from the crus of the diaphragm to the bifurcation of the aorta. F) ZAHVAĆANJE NŽ --89% of adrenal involvement occurred when the renal tumor was in the upper pole or was multifocal --when renal vein involvement was present, there was a greater likelihood of spread to the ipsilateral adrenal gland --ostali kriteriji: tumor size larger than 5.5 cm, clinical category T3 or greater, and the presence of lymph node or distant metastasis --100% negative predictive value of CT in the detection of adrenal gland involvement --If preoperative CT or MRI findings are abnormal and venous tumor extension, upper pole tumors, or tumors larger than 7 cm are present, the authors recommend adrenalectomy --JOŠ NEKI MOGUĆI ZNAKOVI KOJI UPUĆUJU NA ZAHVAĆANJE NŽ ---adrenal enlargement ---displacement ---or nonvisualization was associated with malignant spread in 24% of cases; adrenalectomy should be performed in these patients G) ZAHVAĆANJE OKOLNIH STRUKTURA (T4) --disease of patients with T4 lesions often is downstaged after surgical resection, which is why we offer surgical resection to all patients with suspected T4 disease who are physically able to tolerate surgery and have lesions considered resectable --involved structures are most commonly the colon, pancreas, diaphragm, liver, spleen, and bowel mesentery --difficulty in evaluating patients eligible for surgical resection lies in preoperatively determining the extent of RCC involvement outside of the Gerota fascia - LOŠA PREDIKTIVNA VRIJEDNOST PRIMJER: -Margulis et al. [46] identified the cases of 30 patients with suspected T4 disease at preoperative evaluation. -In 18 of the 30 cases (60%), disease was downstaged after complete surgical resection showed the poor predictive value of adjacent organ involvement on preoperative images. -Better preoperative assessment of adjacent organ invasion would be of great benefit because patients with pathologically confirmed T4 disease had a median survival period of only 2.3 months, raising the question whether surgical resection provided any benefit to these patients. Direct extension of renal cell carcinoma outside the Gerota fascia into neighboring organs (stage T4a) is difficult to diagnose with certainty unless there is a demonstrable focal change in attenua- tion within an organ. Loss of tissue planes and irregular margins between the tumor and surrounding structures raise the possibility of direct infiltration and can be seen in up to 15% of patients without surgically confirmed stage T4a disease. 18. MULTIFAZNI MDCT - PROTOKOLI A. corticomedullary phase is an arterial phase acquisition that we usually perform 25- 30 seconds after initiation of contrast -- drugi članak kaže 25-70s / the contrast material is primarily within the cortical capillaries, peritubular spaces, and cortical tubular lamina and has not yet filtered through the more distal renal tubules / maximal opacification of the renal arteries and veins occurs, allowing confident diagnosis of venous extension of tumoral tissue / hypervascular metastases to the liver, spleen, and pancreas are most conspicuous in this phase B. nephrographic phase between 60 and 80 seconds (80-100???) -- drugi članaka kaže 80-180 / nephrographic phase is the most valuable for detecting renal masses and characterizing indeterminate lesions C. A number of investigations have shown that the nephrographic phase is superior for renal cell carcinoma conspicuity and detection -nephrographic phase unveiled 1.3 times more masses in cortex and 5.3 times more lesions in medulla, compared with the corticomedullary phase D. excretory phase is performed in combination with the corticomedullary or nephrographic phase, is acquired after a 5- to 8-minute delay (drugi članak - excretory phase begins approximately 180 seconds after the initiation of injection of iodinated contrast material), and results in opacification of the renal collecting system / collecting system is best visualized using coronal multiplanar reformation and volume rendering to simulate a conventional excretory urography / better delineate the relationship of a centrally located mass with the collecting system and define potential involvement of the calices and renal pelvis / measurement of the washout of contrast material from a lesion at 15 minutes allows differentiation between hyperdense cysts and renal neoplasms (all lesions that proved to be neoplasms at surgery or follow-up studies showed a decrease in attenuation or "deenhancement" of at least 15 HU at delayed CT) E. proper timing of contrast-enhanced acquisitions is very important / patients with cardiac disease, use of fixed delays can result in the corticomedullary phase corresponding to a very early arterial acquisition F. obstructed kidney enhances later, such that the nephrographic phase and excretory phase will occur at a later time, in comparison with the contralateral side G. lesion may be most conspicuous during the normal excretory phase H. if a small renal mass is located within the medulla, it may not be identified during the corticomedullary phase acquisition because of the absence of medullary enhancement and because maximal tumor enhancement occurs during the nephrographic phase I. focal areas of unenhanced medulla can simulate a renal mass during the corticomedullary phase J. some small masses are better visualized in the coronal plane / contour deformation and differential enhancement of the mass become more convincing when compared with the entire kidney displayed in the coronal orientation K. maximum-intensity-projection renderings may make solid renal masses appear less conspicuous, whereas volume rendering (based on voxel attenuation) maintains lesion contrast, especially on the nephrographic phase

DIF.DG. NPL BUBREGA KOJE SADRŽE MAKROSKOPSKU MAST

1. RCC - perirenal fat entrapment, lipid necrosis, or osseous metaplasia, all of which may occur in renal cell carcinoma 2. liposarcoma 3. myolipoma 4. lipoma 5. oncocytoma 6. Wilms tumor

KLJUČNO ZA DIFERENCIJACIJU RCC-a i LIPID-POOR AML-a

1. Recent studies indicate that in contradistinction to RCCs, AMLs with minimal fat show uniform, prolonged contrast enhancement and a higher signal intensity index on double-echo, chemical shift FLASH MRI! 2. Small AML with minimal fat as having an angular interface with the renal parenchyma, demonstrating greater long-to-short axis ratio compared with RCC (> 1.13) or non-clear cell RCC (> 1.29) = ICE CREAM CONE MORPHOLOGY 3. the ability to distinguish between minimal-fat angiomyolipoma (< 25% lipid content at histopa- thology) and clear cell RCC --> low T2 and small size were the only imaging feature, that predicted minimal-fat angiomyolipoma in multivariate logistic regression

PROCJENA ODGOVORA METASTATSKOG RCC-a NA ANTIANGIOGENETSKU TERAPIJU

1. STATISTIKA O POJAVI METASTATSKE BOLESTI -18% of patients with RCC have metastasis at diagnosis (synchronous metastasis) -more than 50% will develop metastatic RCC after nephrectomy during follow-up (metachronous metastasis) with most recurrences (85%) occurring within 3 years -metachronous metastases that manifest after a longer disease-free interval are associated with a better prognosis -more than 90% of patients with metastatic RCC have clear cell RCC -remaining 10% of patients with metastatic RCC have a heterogeneous group of non-clear cell RCC subtypes, including papillary, chromophobe, collecting duct, and unclassified RCC --In a recent study of 194 patients, Chae et al. reported an incidence of recurrence or metastases in 21%, with common sites being lung, bone, the nephrectomy bed and the liver. Tumor recurrence was seen within 2 years in over 80% of patients, the mean time to recurrence being 17 months. 2. PLUĆNE METASTAZE -45% of all metastases from RCC -usually asymptomatic (90% of cases) -multiple nodules (75.6% of cases) or solitary nodules (30.5% of cases) (24) -well circumscribed, round or oval, smaller than 2 cm and in subpleural locations -RCC is one of the well-known causes of "cannonball" metastases (ie, lesions > 5 cm in diameter) -after antiangiogenic therapy, lung metastases of RCC, especially the larger lesions, may show: --necrosis and cavitation --some cases of pneumothorax with necrosis and formation of bronchopleural fistulae in metastatic lesions that have wide contact with the pleura 3. KOŠTANE METASTAZE -large expansile lytic lesions, -most commonly located in the axial skeleton -vertebral bodies are involved more often than the pedicles -lytic lesions are usually extremely destructive and may be associated with an enhancing soft-tissue component -30% of all patients with disseminated RCC -frequent sites of bone metastases are the pelvis, spine, and ribs -solitary bone metastases are rare 4. METASTAZE U LČ -third most common group of metastatic RCC lesions, accounting for 22% of cases -5% of the metastatic LNs are smaller than the upper limit considered as normal (10 mm) -enlarged hyperplastic nodes cannot be differentiated from enlargement that is caused by metastatic disease -primary tumor necrosis or thrombus within the inferior vena cava is associated with a higher rate of reactive lymphadenopathy - false-positive rates (43%) for the 10-mm cutoff -lymph node metastases of RCC are associated with poor prognosis, with a higher incidence of metastatic disease and low response rates to immunotherapy -hypervascular lymph nodes are usually seen in cases of clear cell RCC 5. JETRENE METASTAZE -20% of patients with RCC develop liver metastases -hypervascular lesions with or without central necrosis -chromophobic RCC has a greater propensity to metastasize to the liver -most patients with liver metastases from RCC develop metastases in other locations -the metastatic disease remains limited to the liver in only a small portion of these patients 6. METASTAZE U NŽ -only 9% of patients with RCC -they are usually hypervascular, but they have no characteristic features that allow them to be differentiated from other types of metastases -ill-defined and nodular margins, heterogeneous attenuation, a ring of enhancement, or local invasion; they can also develop central necrosis -CT with normal appearing ardenal glands has a high negative predictive value for adrenal involvement with metastases -usually affect the ipsilateral adrenal gland: --hematogenous dissemination of isolated tumor cells or tumor thrombi through the renal vein, adrenal vein, or collateral veins in the perinephric fat and periphery of the adrenal gland --direct invasion through the renal capsule (classified as stage T4 disease) may occur in large tumors and those in the upper renal pole --metachronous metastases are rare - after nephrectomy, the prevalence of solitary adrenal metastasis to the ipsilateral gland is 3.4% and only 1.1% to the contralateral 7. MOŽDANE METASTAZE -in 8% of the patients with mRCC -enhancing nodules with associated vasogenic edema -usually manifests as a solitary lesion with a hemispheric location, unlike other metastases from other tumors -hypervascularity of the metastatic lesions may lead to spontaneous bleeding 8. ATIPIČNA SIJELA METASTAZA RCC-a a) peritoneal and retroperitoneal metastases -accounting for 7% of all metastases from RCC -enhancing nodules, with or without central necrosis, depending on the size of the nodule -mechanism of perit. mets: a) local spread, which occurs when the RCC breaks the renal capsule and anterior renal fascia, disseminating along the peritoneal surface, and (b) hematogenous dissemination -retroperitoneal metastases usually appear with the development of local recurrence or surgical seeding b) pancreatic metastases -usually develop several years after nephrectomy, and the pancreas may be the sole site of metastatic disease -their appearance may simulate that of neuroendocrine tumors -lesions larger than 1.5 cm may show an area of central necrosis c) isolated splenic lesions -very rare d) pleural metastases -secondary to direct invasion by parenchymal lung lesions e) ovarian metastases -usually unilateral, unlike ovarian metastases arising from other types of tumors, which are generally bilateral 9. PODJELA ANTIANGIOGENETSKIH LIJEKOVA (a) therapy that targets the VEGF (such as small-molecule tyrosine kinase inhibitors) and other key growth factors (such as sorafenib, sunitinib, pazopanib, and axitinib), or in which an injected humanized monoclonal antibody inhibits VEGF (eg, bevacizumab) (b) mTOR inhibitors (eg, temsirolimus and everolimus) 10. KAKO SE UČINAK ANTIANGIOGENETSKIH LIJEKOVA OČITUJE NA IMAGING-u --antiangiogenic therapy decreases tumor perfusion, but it has relatively limited efficacy in shrinking metastases because the mechanism of action of antiangiogenic agents is more cytostatic than cytotoxic --minor response and disease stabilization are seen in more than 70% of cases --complete response to antiangiogenic therapy is uncommon, occurring in less than 1% of cases --changes in tumor perfusion, rather than in tumor size, make these changes more reliable than the classic size criteria for monitoring response to antiangiogenic agents by means of imaging techniques --resistance to treatment develops after 6-12 months of therapy --resistance is specific to the antiangiogenic agent used, and other antiangiogenic agents with different mechanisms of action may be used to treat the metastases --after withdrawing the specific agent for a time (a "drug holiday"), this specific resistance may be reversed Recent phase III clinical trials have used RECIST 1.1 to evaluate the response of metastatic RCC to antiangiogenic drugs (sunitinib, sorafenib, and bevacizumab) and found that these therapies achieved low response rates (10%-30%), despite the significant improvement in overall survival. 11. NAJČEŠĆE NUSPOJAVE --most common side effects include fatigue, vomiting, diarrhea, hypertension, cardiotoxicity, and hand-foot syndrome --bowel toxicity, especially pneumatosis intestinalis and bowel perforation, has been re- ported with anti-VEGF and VEGFR agents in- cluding bevacizumab, sunitinib, and sorafenib (class-specific anti-VEGF effects compromising bowel wall integrity, intestinal wall disruption due to necrosis of the serosal tumor deposits, impaired healing of pathologic or surgical bowel injury, and ischemia related to mesenteric throm- bosis - in the case of bevacizumab) --VEGF-directed agents, especially bevaci- zumab but also sunitinib and sorafenib, can al- ter the hemostatic balance by interfering with the integrity of the endothelial cells, leading to both hemorrhagic and thromboembolic episodes - bevacizumab can cause pulmonary hemorrhage leading to massive hemoptysis; this complication is seen as areas of ground-glass attenuation with or without interlobular septal thickening (i.e., crazy paving pattern) on CT / bevacizumab is also associated with a significantly increased risk of arterial and venous thromboembolism including pulmonary embolism --drug-associated interstitial lung disease (e.g., drug-related pneumonitis) is a class-specific effect of mTOR inhibitors, including temsirolimus and everolimus, that is seen in up to 40% patients - in approximately half of the cases, drug-associated interstitial lung disease is asymptomatic / usual presentation is with bilateral symmetric lower lobe-predominant ground-glass or reticular opacities 12. KRITERIJI ZA PROCJENU UČINKA ODGOVORA a) Choi criteria --was made to detect the efficacy of imatinib in patients with gastrointestinal stromal tumours (GIST) --> that drug induces considerable tumour necrosis, which can be accompanied by a paradoxical increase in tumour size, thus simulating progression --PR: is defined as a decrease greater or equal to 10% in a tumour size measurement or a reduction greater or equal to 15% in the attenuation of target lesions measured using contrast-enhanced CT --PD: defined as an increase in size greater or equal to 10% that does not meet the PR criteria through a change in attenuation --Choi criteria have a significantly better predictive value for overall survival than RECIST 1.1 at the first posttreatment evaluation --Choi criteria produced results similar to those achieved with RECIST 1.1 at subsequent follow-up examinations --use of these criteria, therefore, does not change the clinical management of these patients b) modified Choi criteria -measurements in the arterial phase, unlike other criterias in the portal phase -razlika prema klasičnim Choi kriterijima: there needs to be a reduction both in terms of the size and attenuation of target lesions, to define an objective response c) Size and Attenuation CT (SACT) criteria --Attenuation measurements were obtained using volume of interest (VOI) --POSITIVE RESPONSE IS DEFINED AS: • a reduction in size greater or equal to 20%; • OR a reduction in mean attenuation greater or equal to 40 HU in at least one target lesion (excluding the lungs); • OR a reduction in size of the tumour greater or equal to 10% and a reduction in mean attenuation greater or equal to 20 HU in half of the target lesions (excluding the lungs) d) MASS criteria 13. NEDOSTACI SPOMENUTIH KRITERIJA A. It is essential to use the same CT acquisition protocol / no standardization on what phase should be used / Choi criteria and MASS criteria use the portal venous phase, whereas the modified Choi criteria use the arterial phase. B.There is a lack of agreement about the best technique for measuring attenuation.There is no consensus regarding the placement of the ROI, that is, whether the ROI should encompass the whole lesion (as in the Choi and modified Choi systems) or only a part of the lesion (as in the MASS system and its central fill-in). Nor is there consensus on whether the evaluation of attenu- ation should be qualitative (as in the Choi and modified Choi systems) or quantitative (as in the MASS criteria). C. Comparison between studies that use the same imaging phase—in the same institution and in different institutions—depends on many other factors such as cardiac output (which is of paramount importance in patients treated with antiangiogenic agents, because of their cardio- toxic effects), type of contrast agent, start of the contrast material injection, kilovoltage, and use of different scanners. 14. QUANTITATIVE CT PERFUSION PARAMETERS -ove metode se mogu koristiti sa svima dinamičkim kontrastnim pretragama - CT, US, MRI -in the quantitative analysis, it is possible to evaluate: --blood flow, which expresses the rate of delivery of blood (oxygen and nutrients) to the tumor --blood volume, which represents the functional microvessel density (ie, the volume of the vascular network that is functional in the tumor) --permeability or k-trans, which describes the rate of contrast material leakage into the extra- cellular space Quantitative functional CT parameters have proved to be reproducible in body tumors and to have good interobserver and intraobserver agreement, although measurements obtained with different methods of analysis are not directly interchangeable. Patients in whom the tumor blood flow decreased more than 50% after a single cycle of treatment had a longer median overall survival (20 months) compared with patients whose tumor blood flow decreased 50% or less (13 months). 15. MOGUĆA ULOGA CT PERFUZIJE A. perfusion changes normally appear before changes in size B. early identification of progressive disease by means of blood flow measurements would enable clinicians to consider a change in therapy, including dose or schedule modifications or switching to another agent before tumor growth is documented C. tumors exhibiting this phenomenon could then be easily singled out for targeted biopsy and extraction of the resistant cells for study 16. ULOGA RECIST-a / modified RECIST --PFS (progression free survival) as the criterion of clinical benefit --modified RECIST: reduction of at least 10% in the sum of the greatest diameters proved to be the threshold which best distinguished responders with median PFS of 11.1 months, from non-responders with median PFS of 5.6months --during the first cycle of treatment, 73% of patients were detected as responders according to the −10% threshold, while only 19% of patients had a response according to RECIST criteria (threshold of −30%) 17. ULOGA PET-a --the use of [18F] FDG PET in patients with mRCC is limited, because RCCs and their metastases have a low rate of glucose metabolism --negative [18F] FDG result does not exclude the presence of RCC --Evaluation of [18F]-FMISO PET/CT - [18F]-fluoromisonidazole ([18F]-FMISO) --labelled with 18F, FMISO allows tumour hypoxia to be imaged by PET 18. ULOGA DWI --few data are available concerning the effect of antiangiogenic treatments on perfusion or diffusion in the tumours. In addition, there is no consensus in the literature concerning the choice of b values 19. ULOGA BOLD MRI-a --Blood Oxygenation Level-Dependent MRI (BOLD MRI), also called intrinsic susceptibility imaging, is a technique which is sensitive to tissue oxygenation --called intrinsic susceptibility imaging, is a technique which is sensitive to tissue oxygenation --haemoglobin in its deoxygenated form has paramagnetic properties, i.e. it modifies the local magnetic field in a tissue --this means that there is a signal loss proportional to the amount of deoxyhaemoglobin in the red blood cells of the vessels of a tissue, provided that a suitable sequence is performed known as a gradient echo sequence --however, it follows that the signal loss is also influenced by other factors such as the amount of red blood cells in the tissue, itself related to the number of vessels (the blood volume), and the velocity of blood circulation (blood flow) --it has been shown that the R2* value of tumours decreases dose-dependently with antivascular treatment in prolactinoma and fibrosarcoma models. There have not yet been any studies analysing the usefulness of BOLD MRI in the response to anti-angiogenic treatment in humans

AGRESIVNIJI OBLICI RCC-A

1. ccRCC 2. collecting duct carcinoma (Bellini duct carcinoma) RCC 3. medullary cystic RCC 4. unclassified RC

PREPORUKE ŠTO S PACIJENTIMA KOJI IMAJU AML

1. conservative observation and follow-up examinations of asymptomatic patients with tuberous sclerosis and angiomyolipoma are recommended with biannual imaging that may include US, CT, or MR imaging 2. pregnancy may also be a justification for more aggressive treatment and follow-up given the evidence for significant hormonal influence on tumor growth and hemorrhage 3. particular attention to uncharacteristic lesions is recommended due to the rare association between angiomyolipoma and synchronous malignant neoplasms such as renal cell carcinoma and malignant epithelioid angiomyolipoma 4. these tumors do not have to be large (4 cm in diameter) before serious life-threatening hemorrhage can occur, as previous studies have suggested, and at least one study has shown that smaller tumors less than 4 cm in diameter have a more rapid doubling time

INDOLENTNIJI OBLICI RCC-A

1. pRCC 2. crRCC 3. multilocular cystic RCC 4. mucinous tubular and spindle RCC 5. RCC associated with neuroblastoma

PROGNOZA RCC-a

5- and 10-year disease-free survivals: --T1 - 95% and 91% --T2 - 80% and 70% --T3a - 66% and 53% --T3b - 52% and 43% --T3c - 43% and 42%, respectively

SEGMENTAL ENHANCEMENT INVERSION

A schema of segmental enhancement inversion and a case of a 76- year-old woman with right renal oncocytoma demonstrating segmental enhancement inversion. a Schema of segmental enhancement inversion. 1. A tumour shows two distinct areas of hyper-enhancement (white) and hypo-enhancement (dark grey) on the corticomedullary phase (30-40 s). Hyper- and hypo-enhancing areas consist of higher and lower cellularity components, respectively. 2. On the early excretory phase (120-180 s), the higher cellularity component becomes relatively low attenuation due to contrast washout. The lower cellularity component becomes relatively high attenuation due to gradual enhancement of oedematous stroma. Therefore, contrast enhancement of these two distinct areas reverse between the corticomedullary (1) and the early excretory (2) phases. The peak enhancement of the oedematous stroma and the optimal timing of segmental enhancement inversion may be variable in each tumour. b The corticomedullary phase of the axial contrast-enhanced (CE) computed tomography (CT) demonstrates an intensely enhancing mass with a small central portion of low attenuation (arrow). c The low attenuation central portion in the nephrographic phase is relatively hyperattenuating in the corticomedullary phase (arrow); the relative enhancement is reversed. d The delayed phase shows the mass to be nearly homogeneous (arrow). e (Low magnification) Oncocytoma, in addition to the tightly packed nests of tumour cells (T), less densely arranged nests are located in an oedematous stroma (arrows)

BOSNIAK CLASSIFICATION

Bosniak I --simple cyst --imperceptible wall, rounded --work-up: none --percentage malignant: ~0% Bosniak II --minimally complex --a few thin <1 mm septa or thin calcifications (thickness not measurable); --non-enhancing high-attenuation (due to proteinaceous or hemorrhagic contents) renal lesions <3 cm --these lesions are generally well marginated --work-up: none --percentage malignant: ~0% Bosniak IIF --minimally complex --increased number of septa, minimally thickened with nodular or thick calcifications --there may be perceived (but not measurable) enhancement of hairline-thin smooth septa minimal thickening of the wall with perceivable enhancement --hyperdense cyst >3 cm diameter, mostly intrarenal (less than 25% of wall visible); no enhancement --requiring follow-up (the 'F' in 2F is for 'follow'): needs ultrasound/CT/MRI follow up - no strict rules on the time frame but reasonable at 6 months --percentage malignant: ~5% Bosniak III --indeterminate --thick, nodular multiple septa or wall with measurable enhancement --treatment/work-up: partial nephrectomy or radiofrequency ablation in elderly or poor surgical candidates --percentage malignant: ~55% Bosniak IV --clearly malignant --solid mass with a large cystic or a necrotic component --treatment: partial or total nephrectomy --percentage malignant: ~100%

OSSIFYING RENAL TUMOR OF INFANCY - DJECA

DEFINICIJA -a rare benign renal mass, with only 11 cases reported in the literature, EPIDEMIOLOGIJA -age from 6 days to 14 months KLINIČKA SLIKA -10 of 11 having hematuria as the presenting symptom -boys are more commonly PHD -9/11 cases occurred in the left kidney -7/11 cases the upper pole calices -arise from urothelium and is attached to the renal medulla, specifically the papillary region of the renal pyramids -extends in a polypoid fashion into the collecting system -more than 2-3 cm in diameter IMAGING -renal outline is usually maintained -filling defects with partial obstruction of the collecting system -ossification - may mimic a staghorn calculus, (exceedingly rare in the age group in which this lesion occurs) -dvoje ih se nije prezentiralo s kalcifikatima -US - mass is echogenic with shadowing, and hydronephrosis may be present -CT shows a well-defined mass, often calcified, with poor enhancement TIJEK BOLESTI -biologic behavior of ossifying renal tumor of infancy appears to be benign, with no reported cases of malignant spread and postsurgical disease-free survival at follow-up lasting from 4 months to 23 years

MULTILOCULAR CYSTIC RENAL TUMOR - DJECA = MULTICYSTIC NEPHROMA

DEFINICIJA -encompasses a spectrum ranging from a purely cystic lesion lined by epithelium and fibrous septa with mature tubules (cystic nephroma) to a lesion in which the septa contain foci of blastemal cells (cystic partially differentiated nephroblastoma) -benign mixed mesenchymal and epithelial neoplasm of the kidney EPIDEMIOLOGIJA -tend to manifest at two age peaks --in children aged 3 months to 4 years (predominantly boys with cystic partially differentiated nephroblastoma) / M:Ž = 3:1 --in adults (predominantly women with cystic nephroma) / 40-70 godina KLINIČKA SLIKA -painless abdominal mass IMAGING -well-circumscribed, encapsulated mass consisting of multiple cysts from several millimeters to 4 cm in diameter, with variably enhancing septa and no excretion of contrast material into the loculi -absence of solid components and of vascular abnormalities and the presence of homogeneous renal parenchyma suggest benignity of a renal mass -US is best at demonstrating its multicystic structure -tumor may or may not extend beyond the renal capsule -herniation into the renal collecting system -unilateral mass with irregular cysts and septa of variable thicknesses - BOSNIAK III -cross-sectional imaging techniques of CT, ultrasound, and MRI show the multilocular cystic features of MLCN but unfortunately cannot be used to accurately differentiate MLCN from other complex cystic renal masses, particularly a subset of cystic renal cell carcinomas DIF.DG. -unilateral autosomal dominant polycystic kidney disease -localized cystic disease of the kidney -any solid childhood renal neoplasm may undergo hemorrhage and necrosis and look like a multilocular cystic renal tumor --less than 10% of Wilms tumors -multicystic dysplastic kidney (MCDK) can be differentiated from cystic nephroma owing to the absence of normally functioning renal parenchyma and to symmetric contrast material excretion at CT by the remaining normally functioning parenchyma in patients in whom a large portion of the kidney has been replaced by cystic nephroma --segmental MCDK may occur in the obstructed moiety (typically the upper pole moiety) in patients with complete ureteral duplication --it may be possible to distinguish segmental MCDK from cystic nephroma without evidence of complete duplication TERAPIJA -ekscizija -ako dođe do recidiva - local radiation therapy or chemotherapy -metastatska bolest nije zapažena

MEDULARNI KARCINOM - DJECA

DEFINICIJA -highly aggressive malignant tumor of epithelial origin that occurs almost exclusively in adolescent and young adult blacks with sickle cell trait or hemoglobin SC disease but not with homozygous hemoglobin SS (sickle cell) disease EPIDEMIOLOGIJA -Age range is 10-39 years with a mean age of 20 years -less than 25 years of age, there is a male-to-female ratio of 3:1 -in those older than 25 years there is no gender predominance KLINIČKA SLIKA -gross hematuria -abdominal or flank pain -weight loss -palpable mass -fever PHD -thought to arise at the renal pelvic-mucosal interface -quickly grows to fill the renal pelvis and invade vascular and lymphatic structures -intraparenchymal satellite nodules are frequently present IMAGING -centrally located infiltrative lesion invading the renal sinus with peripheral caliectasis -reniform enlargement + smaller peripheral satellite nodules -heterogeneous enhancement at CT -shows heterogeneous echotexture at US DIF.DG. -transitional cell carcinoma -rhabdoid tumor PROGNOZA -extremely poor -responds poorly to chemotherapy or radiation therapy, with a mean survival of 15 weeks from diagnosis

MESOBLASTIC NEPHROMA - DJECA

DEFINICIJA I EPIDEMIOLOGIJA -often referred to as fetal renal hamartoma or leiomyomatous hamartoma -najčešći solidni tm bubrega u neonatusa -identificira se najčešće unutar prva 3 mj života (90% unutar 1. godine) -slight male predominance KLINIČKA SLIKA -palpable abdominal mass, with hematuria less frequent ELEMENTI KOJI MOGU PONUKATI SUMNJU -polyhydramnios -hydrops -premature delivery -increased renin levels PHD -gross analysis, the tumor has a rubbery ap- pearance, similar to a uterine leiomyoma -tends to be a large infiltrative mass with ill-defined margins and no capsule IMAGING -velika masa -obično zahvaća renalni sinus -may contain cystic, hemorrhagic, and necrotic regions -česta je lokalna infiltracija perinefričkog tkiva TERAPIJA -generally exhibits benign behavior -successfully treated with nephrectomy alone -rarely, the lesion may recur locally if incompletely resected -it can metastasize to the lungs, brain, or bones Prognosis is best if the tumor is diagnosed and resected before 6 months of age

LYMPHOMA - DJECA

DEFINICIJA -lymphoma commonly involves the kidney sec- ondarily from direct retroperitoneal extension or hematogenous metastases -non- Hodgkin lymphoma—especially Burkitt lymphoma - najčešći oblik -existence of primary lymphoma in the kidney is unlikely - renal paren- chyma does not contain lymphatic vessels KLINIČKA SLIKA -typically no symptoms until late in the disease -flank or abdominal pain -hematuria, anemia -weight loss -palpable mass IMAGING 1. Oblici bolesti -variable -solitary renal mass or nodule -multiple renal masses or nodules that occasionally distort the renal contour and displace the collecting system - most common -diffuse infiltration - reniform enlargement -direct invasion from contiguous retroperitoneal extension -least commonly isolated perinephric disease - can arise from retroperitoneal disease (most commonly) or transcapsular spread of parenchymal involvement ---CT findings of perinephric disease are variable and include small curvilinear areas of high attenuation, soft-tissue attenuation nodules, thickening of the Gerota fascia, or a mass contiguous with retroperitoneal disease ---isolated perirenal space disease is rare, typically manifesting as a hypoechoic rim or plaque of tissue surrounding the kidney that is hyperattenuating at nonenhanced CT and hypoattenuating at contrast-enhanced CT 2. Imbibicija -homogeneous -hypoattenuating on nonenhanced and contrast-enhanced images -may mimic multiple renal cysts -US - hypoechoic and may demonstrate increased through transmission

METANEPHRIC ADENOMA - DJECA

DEFINICIJA -nephrogenic adenofibroma or embryonal adenoma -benign renal tumor that can occur at any age -peak age of occurrence in the fifth or sixth decade and a 2:1 female preponderance EPIDEMIOLOGIJA -any age -female -no bilateral cases have been reported KLINIČKA SLIKA -pain, hypertension, hematoma, a flank mass, hypercalcemia, and polycythemia -polycythemia, a characteristic finding seen in approximately 10% of patients with metanephric adenoma, promptly disappears after surgical resection IMAGING -at US, the mass is well defined and solid. It can be hypoechoic or hyperechoic or even cystic with a mural nodule / Doppler evaluation shows the lesion to be hypovascular -at CT performed before intravenous administration of contrast material, the mass may be isoattenuating or hyperattenuating and small calcifications may be present / enhances less than normal renal parenchyma -at MRI - hypointense signal on T1- weighted MRI and a slightly hyperintense signal on T2-weighted MRI

RHABDOID TUMOR - DJECA

DEFINICIJA -riječ je o vrlo agresivnom tumoru koji patohistološki nalikuje tumoru muskuloskeletnog podrijetla s time da stanice nisu miogenog podrijetla EPIDEMIOLOGIJA -2% of pediatric renal malignan- cies -80% occur in patients less than 2 years of age and 60% in patients less than 1 year of age, with the majority (25%) diagnosed between 6 and 12 months of age / može sve do 9. godine -M:Ž = 1.5:1 KLINIČKA SLIKA -hematuria -simptomi kao posljedica metastatske bolesti POVEZANOST S DRUGIM PATOENTITETIMA -synchronous or metachronous primary intracranial masses or brain metastases --primitive neuroectodermal tumor --ependymoma --cerebellar and brainstem astrocytoma -hypercalcemia secondary to elevated parathormone levels / after resection, the serum calcium level tends to normalize IMAGING -large, centrally located, heterogeneous soft-tissue mass involving the renal hilum with indistinct margins -vaskularna i lokalna invazija često prisutna -vrlo agresivan, rano metastazira - liver, abdomen, brain, lymph nodes, or skeleton -KAKO GA RAZLIKOVATI OD WT: --subcapsular fluid collections --tumor lobules separated by dark areas of necrosis or hemorrhage --linear calcifications outlining tumor lobules Survival is poor, with an 18-month survival rate of only 20%.

ROSAI-DORFMAN DISEASE

DEFINICIJA -sinus histiocytosis with massive lymphadenopathy - non-neoplastic histiocytic disorder with massive lymphadenopathy due to infiltration and dilation of the lymph node sinuses by large histiocytes KLINIČKA SLIKA -massive, diffusely enlarged, bilateral, non-tender cervical lymphadenopathy -kidney involvement is rare in this patient group and seen in 4% of patients IMAGING -renal involvement may be seen as discrete nodal masses or infiltrative lesions around the capsule -nodal masses are isodense on unenhanced CT with mild enhancement after contrast injection DIF.DG. -differential diagnosis of Rosai-Dorfman disease is not straightforward and may include: --lymphoma --lymphangioma --renal cell carcinoma --metastasis

CLEAR CELL SARCOMA - DJECA

DEFINICIJA -tumor bubrega u djece koji metastazira u kosti EPIDEMIOLOGIJA -4%- 5% of primary renal tumors in childhood -pik - 1-4 god KLINIČKA SLIKA -nonspecific presentation - abdominal mass IMAGING -do not allow differentiation of clear cell sarcoma from Wilms tumor -sharply demarcated solid intrarenal mass without intravascular extension -recidiv - često, čak i nakon više godina od nefrektomije -metastaze: bones, lymph nodes, brain, liver, and lungs TERAPIJA -nephrectomy and chemotherapy -current long-term survival rates of 60%-70%

ANGIOMIOLIPOM - DJECA

DEFINICIJA -uncommon tumor that consists of a disordered arrangement of vascular, smooth muscle, and fatty elements -hamartoma vs. benigni tm SPORADIČNO VS. NASLJEDNO -most often occur sporadically -may occur in 40%-80% of patients with tuberous sclerosis -associated with neurofibromatosis and von Hippel-Lindau syndrome EPIDEMIOLOGIJA -mean age at presentation is 41 -4:1 female predominance -in children angiomyolipomas are rare in the absence of tuberous sclerosis (but 80% if they have TS) KLINIČKA SLIKA -larger than 4 cm in diameter --> hemoragija --flank or abdom. pain --hematurija --životno-ugrožavajuća hemoragija - Wunderlich syndrome IMAGING -CT scans and MR images are diagnostic when fat is found within the mass -US demonstrates highly echogenic nonshadowing foci, which correlate with the fatty elements --> + redovito praćenje djece s TS -Although fat is occasionally seen in Wilms tumor and renal cell carcinoma, the diagnosis of angiomyolipoma is typically straightforward in the appropriate clinical setting -jako rijetko - vask invazija i met. u LČ TERAPIJA -lezije > 4cm--> partial nephrectomy or selective catheter embolization to prevent potentially life-threatening hemor- rhage -kod djece s TS bitno je biti poštedan prema funkcionalnom bubrežnom parenhimu

RCC CAUSING A LARGE ARTERIOVENOUS FISTULA - image

Drawing illustrates a large arteriovenous (A-V) fistula within a renal tumor. The fistula is associated with intense venous flow to the left renal vein and periureteral veins that causes ureteral notching.

RCC - DJECA

EPIDEMIOLOGIJA -has been reported in patients less than 6 months of age -rare in children - <7% tm bubrega u prva dva desetljeća -WT:RCC = 30:1 -povezan s VHL sy, naročito u bilat. tm KLINIČKA SLIKA -bezbolna hematurija (češće nego u WT) + bol u lumbalnoj loži + palpabilna masa IMAGING -infiltrative solid mass with variable necrosis, hemorrhage, calcification, and cystic degeneration -morfološki sličan WT -dimenzijom obično manji od WT -kalcifikati se vide češće u RCC (25%) nego u WT (9%) -metastases to the lungs, bones, liver, or brain are found in 20% of patients at diagnosis -RCC se češće manifestira bilat i češće metastazira u kosti -th: radical nephrectomy and regional lymphadenectomy / extremely resistant to chemotherapy

GROWTH PATTERN OF RENAL MASSES: BALL VERSUS BEAN

I. BALL 1. RCC 2. AML 3. Oncocytoma 4. Metastatic 5. Lymphoma II. BEAN 1. TCC 2. Metastasic 3. RCC (infiltrative) 4. Medullary carcinoma 5. Collecting duct carcinoma

MEZENHIMALNE NEOPLAZME BUBREGA

I. BENIGN MESENCHYMAL NEOPLASMS OF THE KIDNEY 1. ANGIOMYOLIPOMA -most common -composed of variable proportions of mature adipose tissue, dysmorphic blood vessels, and smooth muscle -pripada obitelji PEC-omas (perivascular epithelioid cell tumors) -sporadical AML - 50-70% -inherited 30-50% -SPORADIC ANGIOMYOLIPOMA develops during the 4th to 6th decade, with a 4:1 female preponder- ance, and usually manifests with flank pain, hematuria, and a palpable mass -ANGIOMYOLIPOMA IN PATIENTS WITH TUBEROUS SCLEROSIS --develops early in life (3rd to 4th decade), without any sex predilection - ALI DRUGI ČLANAK KAŽE ŽENE??? --often symptomatic at presentation and are associated with an increased risk of hemorrhage --lesions from patients with TSC were significantly more likely to express both estrogen receptors and progesterone receptors, compared with lesions from patients with sporadic angiomyolipomas --in female patients during adolescence and pregnancy may be caused by hormonal influence --multiple and bilateral TIPOVI AML-a - phd a) TRIPHASIC (CLASSIC) b) MONOTYPIC EPITHELIOID -8% of renal angiomyolipomas, show a high degree of association with tuberous sclerosis, and demonstrate aggressive behavior -occasional extension into the renal vein or VCI TIPOVI AML-a - imaging a) CLASSIC TRIPHASIC RENAL ANGIOMYOLIPOMA -heterogeneous mass with varying proportions of macroscopic fat, intralesional aneurysms, and hypervascular soft tissue -diffusely hyperechoic masses at ultrasonography -absence of lesion heterogeneity and the presence of speed propagation artifact assist in the accurate differentiation of fat-predominant angiomyolipomas from hyperechoic renal cell carcinomas -macroscopic fat may be confidently imaged with CT or with frequency-selective fat-suppressed pulse sequences at MR b) ANGIOMYOLIPOMAS WITH MINIMAL FAT (THE FAT-POOR VARIANT) -less than 5% of all renal AML -difficult to differentiate from other solid renal tumors -double-echo gradient-echo chemical-shift MR imaging can be used to differentiate fat-poor angiomyolipoma from other renal tumors --differentiation of fat-poor angiomyolipomas from other solid renal masses, the sensitivity and specificity were 96% and 93%, respectively --signal intensity index of more than 25% and with a tumor-to-spleen ratio of -32% or less US -strongly hyperechoic lesion against the backdrop of a hypoechoic renal cortex, because of the multiple tissue interfaces between fatty and non-fatty components of the mass -echogenicity is generally greater than that of surrounding renal parenchyma but should be interpreted with caution because small RCCs may result in a similar appearance -finding of posterior acoustic shadowing is more likely caused by an angiomyolipoma, not an RCC -CEUS --slow centripetal enhancement in the cortical phase and homogeneous enhancement in the peak phase are the main features of solid minimal-fat renal angiomyolipoma --heterogeneous enhancement in patients with RCC during the peak phase ANGIOGRAFIJA -Three patterns were observed, including the typical vascularity seen with angiomatous lesions: --aneurysmally dilated and tortuous vessels, --localized berrylike aneurysms --slow flow-through vessels with holdup of contrast material and relative hypovascularity ------> AV shunting was not an angiographic feature of AML CT -well-marginated cortical predominantly fat- attenuated mass with heterogeneous soft-tissue attenuation interspersed throughout the lesion -soft-tissue attenuation may be the result of hemorrhage or fibrosis, or it may be a manifestation of the vascular or smooth muscle components of the lesion -angiomyolipoma-associated retroperitoneal hemorrhage may mask characteristic fat, rendering differentiation from RCC difficult MRI -fat supression -in predominantly fatty angiomyolipoma, an India ink artifact usually occurs at the interface between the mass and the normal renal parenchyma on opposed-phase T1-weighted images -- bitno za vrlo male AML -appearance of renal angiomyolipoma on T2- weighted images is quite variable, depending on the amount of fat content within the lesion -option of close imaging surveillance, especially by MRI, remains for fat-poor renal angiomyolipomas / biopsija --> ALI because of the risk and fear of bleeding complications, such a lesion can be percutaneously sampled and then immediately treated with (planned) embolization, with the access catheters already in place COMPLICATIONS -include hemorrhage and renal failure -25% of angiomyolipomas may manifest with spontaneous rupture and hemorrhage --tumor size (>4 cm) --presence of intratumoral aneurysms larger than 5 mm -may occasionally grow into the renal vein or the inferior vena cava; this feature may not imply malignant transformation -one-third of monotypic epithelioid angiomyolipomas may show aggressive behavior, with distant metastases to the lungs, liver, and lymph nodes DIF.DG. -lipoma and liposarcoma TREATMENT -total nephrectomy -partial nephrectomy -ablation -arterial embolization MANAGEMENT OF ANGIOMYOLIPOMA -currently, no cure is known for TSC-asso- ciated angiomyolipoma -management focuses primarily on prevention of bleeding and minimization of estrogen exposure, which can promote angiomyolipoma growth -appropriate management of angiomyolipoma is determined not only by lesion size but also by the presence of a hypervascular lesion with aneurysms -drugs that attenuate mTOR function are a type of targeted therapy for TSC-associated angiomyolipoma - sirolimus, everolimus PREPORUKE -currently, in patients with TSC who have large (> 4 cm) and multiple angiomyolipomas who are starting mTOR therapy, we consider the use of angioembolization followed by long-term mTOR inhibition to prevent or slow tumor regrowth, with the hope of ultimately reducing the number of future angioembolizations -patients with large angiomyolipomas or very bulky disease without signs of imminent bleeding can consider adjuvant medical therapy to achieve tumor reduction followed by angioembolization, with reinitiation of therapy occurring after adequate recovery -in patients with multifocal disease in whom all lesions are smaller than 4 cm, it is reasonable to consider medical therapy alone without antecedent angioembolization -MRI should be repeated 6 months after initiation of therapy 2. LEIOMYOMA -tumor may arise from smooth muscle cells of the renal capsule, the muscularis of the renal pelvis, or cortical vascular smooth muscles, with the renal capsule being the most common site -most commonly found in white women CT --well-circumscribed peripherally located hyperattenuating solid mass --relatively homogeneous enhancement on CT images obtained after the administration of contrast material --large tumors - areas of hemorrhage and cystic or myxoid degeneration --peripheral location, well-defined margins, and associated buckling of the renal cortex MR --homogeneously low signal intensity on T1- and T2-weighted images --veći su heterogeni OPREZ --> LARGE LEIOMYOMA indistinguishable from renal cell carcinoma and leiomyosarcoma with imaging studies 3. HEMANGIOMA -single unilateral tumors without any sex predilection -young to middle-aged adults -MOGU BITI POVEZANI S Klippel-Trenaunay syndrome or Sturge-Weber syndrome (oni su povezani s brojnim hemangiomima po tijelu) -most common locations (90%) are the medulla (tip of the papilla) and the renal pelvis -usually smaller than 2 cm and are asymptomatic -hemorrhage is thought to occur as a result of thrombosis, infarction, or neoangiogenesis within the tumor and subsequent mucosal erosion -cavernous hemangiomas are more common than the capillary type CT - lobulated hypo- to isoattenuating soft-tissue mass in the region of the renal medulla or pelvis -multiple phleboliths are an uncommon finding MR -hypointense on T1-weighted images and are hyperintense on T2-weighted images CE -intense arterial enhancement, persisting into the venous phase at CT and MR imaging -may rarely masquerade as a cyst with an en- hancing solid component akin to a cystic renal cell carcinoma TREATMENT -observation -partial nephrectomy -papillectomy -embolization -nephrectomy 4. LYMPHANGIOMA = renal lymphangiectasia or renal lymphangiomatosis -rare benign renal tumor that most often manifests as a multilocular cystic mass in the perinephric or renal sinus region -two-thirds of renal lymphangiomas occur in adults, without any sex predilection -most of them are asymptomatic CT -uni- or multilocular cystic mass in the renal sinus or in the perinephric region -involvement of both kidneys is not uncommon -linear tortuous fluid-filled structures are identified in the retroperitoneum, which are suggestive of dilated lymphatic channels MR -uni- or multilocular cystic mass that is hypointense on T1-weighted images and is uniformly hyperintense on T2-weighted images -signal intensity of the intracystic fluid may be variable, depending on the presence of hemorrhage and debris and the protein content TREATMENT -no treatment is necessary in asymptomatic patients -"Decompensated lymphangiectasia" is the term used for exacerbation, which manifests as an increasing perinephric collection, flank pain, ascites, and hypertension - pregnant patients 5. JUXTAGLOMERULAR CELL TUMOR =reninoma -ORIGIN - myoendocrine cell, a unique modified smooth muscle cell of the juxtaglomerular apparatus with ultrastructural features of both endocrine and smooth muscle -seen in young adults, with a peak incidence in the 2nd and 3rd decades -twice as common in women as in men -KS: severe poorly controlled hypertension, polyuria, polydipsia, and muscle aches -LAB: hypokalemia, high plasma renin activity, and secondary hyperaldosteronism CT -unilateral well-circumscribed hypoattenuat- ing cortical mass -hypovascular mass in the arterial phase despite profuse vascularity, possibly because of renin-induced vasoconstriction -moderate enhancement during the delayed phase MR -cortical-based renal mass of variable signal intensity that shows delayed peripheral enhancement on dynamic contrast-enhanced MR images TRETMAN -kirurška ekscizija 6. RENOMEDULLARY INTERSTITIAL CELL TUMOR =medullary fibroma -arises from interstitial cells of the medulla, which are presumed to be responsible for an endocrine-like antihypertensive action -not associated with blood pressure abnormalities -most tumors are smaller than 5 mm in size and are asymptomatic // ali mogu biti veliki i simptomatski CT -small nonenhancing noncalcified hypoattenuating solid mass within the renal medulla -rarely are larger and may form polypoid masses that protrude into the renal pelvis MR -hypointense on T1- and T2- weighted images because of their rich collagen content with little cellularity TRETMAN -kirurški kod većih i simptomatskih 7. LIPOMA -rare neoplasms -renal cortex is the most common location for intrarenal lipomas -middle-aged women IMAGING -well- circumscribed mass almost exclusively composed of macroscopic fat -MR imaging is the most specific imaging technique for demonstration of both the microscopic and macro- scopic fat of an intrarenal lipoma 8. SOLITARY FIBROUS TUMOR -prije su bili poznati kao hemangiopericitomi -most often found in the pleura -only 40 cases of solitary fibrous tumor of the kidney have been reported -may arise from the renal capsule, cortex, pelvis, or peripelvic connective tissue -older than 40 years, with a slight female predilection -clinical features include a palpable abdominal mass, flank pain, and hematuria -2 tipa: the fibrous type (the most common type) and the cellular type CT -well-circumscribed lobulated soft-tissue mass in the region of the renal sinus or capsule -relatively homogeneous enhancement despite the large size of the mass -necrosis, hemorrhage, and calcifications are rare -na primjeru: lobulated hypoattenuating heterogeneous soft-tissue mass (arrow) in the left kidney MR -isointense to the renal cortex on T1-weighted images -on T2- weighted MR images, alternate areas of extremely low signal intensity and moderately high signal intensity are distributed in a radial configuration TREATMENT -surgical removal is the treatment of choice -most are benign 10%-15% OF EXTRAPLEURAL SOLITARY FIBROUS TUMORS SHOW MALIGNANT BEHAVIOR IN THE FORM OF RECURRENCE OR METASTATIC DISEASE II. MALIGNANT MESENCHYMAL NEOPLASMS OF THE KIDNEY OPĆENITO -primary renal sarcomas of the adult kidney are rare tumors that account for 1%-3% of all malignant renal tumors -before making a diagnosis of primary renal sarcoma, three basic criteria should be met: (a) exclusion of renal metastatic involvement from sarcoma elsewhere in the body; (b) confirmation of renal origin, rather than involvement with a retroperitoneal sarcoma (c) exclusion of sarcomatoid renal cell carcinoma 1. LEIOMYOSARCOMA -most common sarcoma of the adult kidney and accounts for 50%-60% of all renal sarcomas -ORIGIN: renal capsule, the renal parenchyma, smooth muscle fibers of the renal pelvis, or the main renal vein -40 and 70 years of age / M=Ž -KS: flank pain, an abdominal mass, and hematuria -PHD: presence of nuclear pleomorphism, mitoses, and necrosis differentiates leiomyosarcoma from a benign leiomyoma -CT --expansile well-defined solid mass --heterogeneous enhancement with delayed enhancement of the fibrous stroma is also seen --large tumors may show central necrotic areas --rarely, presentation as multilocular cystic mass with peripheral enhancement IZGLED TUMORA OVISNO O PODRIJETLU --tumor arising from the renal capsule may envelop the kidney --if the mass is parenchymal in origin, it may replace large portions of the renal parenchyma, with extension into the perinephric and/or renal sinus fat. --renal pelvic tumors may extend into the collecting system --renal vein leiomyosarcomas may extend into the inferior vena cava -MR --soft-tissue mass with heterogeneous signal intensity that has low-signal-intensity areas on T1- and T2-weighted images --delayed enhancement SPONTANEOUS RUPTURE OF THE KIDNEY HAS BEEN REPORTED IN PATIENTS WITH RENAL LMS TRETMAN -radical nephrectomy is the treatment of choice, which should be followed by postoperative radiation and chemotherapy PROGNOZA -aggressive and rapidly progressive natural history, with a 5-year survival rate of 29%-36% 2. SYNOVIAL SARCOMA -rare soft-tissue malignant tumors that most often occur in the extremities of adolescents and young adults -mean age of 35 years; a slight male predominance -primary renal synovial sarcomas are extremely rare neoplasms, with only 25 cases reported in the literature -KS: abdominal mass, flank pain, and hematuria -CT --large well-circumscribed heterogeneously enhancing soft-tissue-attenuation mass that may extend into the renal pelvis or the perinephric region --some tumors may be predominantly cystic with enhancing septa and mural nodules --extension into the renal vein and inferior vena cava has been described -MR --heterogeneously hyperintense on T2-weighted images and hypointense on T1-weighted images with areas of hemorrhage, fluid levels, and septa -T2 - "triple sign" - intermixed areas of low, intermediate, and high signal intensity TRETMAN -surgical resection, followed by chemotherapy -prognosis for renal synovial sarcoma is extremely poor 3. OSTEOSARCOMA -extremely rare malignant neoplasm, with only 20 cases reported in the literature -BUT -- renal metastases from primary skeletal osteosarcoma are more common and are found at autopsy in 10%-12% of patients -older patients (mean age, 61.5 years), with male and female patients equally affected -nonspecific symptoms that include weakness, abdominal pain and distention, weight loss, and gross hematuria -KAKO NASTANE --metaplastic theory has been proposed that suggests dedifferentiation of connective tissue into embryonic mesenchyme that then differentiates into osteoblasts, with subsequent bone formation -IMAGING --ill-defined large peripheral renal mass with calcifications or ossification --characteristic "sunburst" calcification has been described for renal osteosarcoma --perinephric extension and distant metastases to lung and liver are common -prognosis is extremely poor (mean survival, 8-22 months) despite an aggressive therapeutic approach including radical nephrectomy, radiation, and chemotherapy 4. FIBROSARCOMA -extremely rare malignancy of the kidney, with only a few cases reported in the literature -patients older than 40 years; both sexes are affected equally -palpable abdominal mass, hematuria, and flank pain -ORIGIN: arise from the renal capsule, which is rich in fibrous tissue IMAGING --large heterogeneously enhancing soft-tissue mass --perinephric or retroperitoneal extension is commonly observed -no typical imaging findings differentiate fibrosarcoma from other renal malignancies -radical nephrectomy is the treatment of choice -aggressive malignancy with 5-year survival rates as low as 10% III. OSTALI RIJETKI TUMORI 1. PRIMITIVE NEUROECTODERMAL TUMOR OF THE KIDNEY - PNET -adolescents and young adults -imaging features of a PNET are indistinguishable from RCC -large mass with near-total replacement of the renal parenchyma -heterogeneous mass on CT -low signal-intensity solid mass with lobulated contours on T1-weighted images and heterogeneous signal intensity on T2-weighted images -may extend to the renal veins and inferior vena cava 2. LIPOSARCOMA -20% of all soft-tissue sarcomas in adults -most commonly detected at 50-65 years of age with male predominance -primary renal capsule malignancies are uncommon -primary liposarcoma of the renal capsule is an extremely rare disease with only about 20 cases reported -5 histological subtypes, including well-differentiated, dedifferentiated, myxoid, round cell, and pleomorphic -most important clinical entity in the differential diagnosis is macroscopic fat-containing angiomyolipoma 3. PRIMARY MALIGNANT NEUROENDOCRINE TUMOR OF THE KIDNEY -neuroendocrine tumors of the kidney are extremely rare neoplasms and include carcinoids, atypical carcinoids, and small cell carcinomas -HIGH INCIDENCE OF A HORSESHOE KIDNEY -50s and 60s but patients as young as 12 years and those in their 70s have also been reported - older age at the time of diagnosis (> 40 years) is correlated with an advanced disease stage and a worse prognosis -IMAGING --calcification --heterogeneous on ultrasound (US) and CT, carcinoids of the kidney have a characteristic tendency to show minimal or poor enhancement on contrast-enhanced CT, corresponding to hypovascular or avascular lesions on renal angiography -octreotide scanning has been recently proposed as a sensitive imaging modality for diagnosing and evaluating the extent of disease -liver mets 4. MALIGNANT FIBROUS HISTIOCYTOMA OF THE KIDNEY -rare tumor, and < 100 cases have been reported -arises from the kidney capsule or renal parenchyma and represents 6% of renal sarcomas -IMAGING --bulky tumors with extra-renal extension --tend to recur locally --well-defined soft tissue mass with inhomogeneous minimal enhancement with slightly higher attenuation than the skeletal muscle on contrast-enhanced CT --decreased attenuation corresponding to regions of myxomatous tissue, cystic degeneration, hemorrhage, or necrosis is observed on CT --hypointense to kidney parenchyma on T1-weighted images, whereas they appear iso- or hyperintense on T2- weighted images / hypointense areas on T1- and T2- weighted images reflect the fibrous components of the tumor and are a potentially useful clue for an imaging 5. METASTATIC OSTEOSARCOMA OF THE KIDNEY -metastatic disease of the kidney is not common -mostly seen in patients with a neoplasm of the lung, breast, gastrointestinal tract, or melanoma IMAGING -often bilateral -extensive calcification on radiographs, occasionally in a sunburst pattern, and may even be detectable on plain radiography -clinically occult metastatic renal osteosarcoma is not rare and can be seen in 10% of autopsies of patients who die from osteosarcoma

RENALNI PSEUDOTUMORI - POJAVE KOJE IMITIRAJU NEOPLAZME

I. DEVELOPMENTAL RENAL PSEUDOTUMORS 1. PROMINENT COLUMNS OF BERTIN -normal variant of the kidney formed of hypertrophied cortical tissue located between the pyramids that projects into the renal sinus, resulting in splaying of the sinus -not only distorts the renal sinus but can also result in what appear to be bizarre or disorganized calyces on excretory urography or CT urography because the papillae are not situated in the typical radial orientation -middle third of the kidney, more commonly the left kidney than the right -US --"indentation on the renal sinus by the lesion, splitting of the sinus --well defined and distinct from the renal sinus, in continuity with the adjacent renal cortex, with similar echogenicity as that of adjacent renal cortex --engulfment of the papilla --cortical projection due to extension of the junctional parenchyma medially in the kidney" --similar echogenicity to the adjacent renal cortex or more echogenic than the normal renal cortex as a result of the anisotropic effect -CECT or MRI - enhancement (perfusion) to be similar to that of surrounding renal parenchyma 2. DROMEDARY HUMP -focal bulge on the lateral border of the left kidney -result of the adaptation of the kid- ney to the adjacent spleen -can usually be easily diagnosed on sonography and has the same perfusion as the surrounding renal parenchyma on contrast-enhanced sonography 3. PERSISTENT FETAL LOBULATION (LOBATION) -usually diminishes by the end of the fetal period -sometimes these lobulations persist into adulthood, and if not correctly identified, may be misdiagnosed as a renal tumor or a scarred kidney -by the presence of renal surface indentations that overlie the space between the pyramids -persistent fetal lobulation of the kidney can be confirmed by documenting the presence of a renal pyramid in the bulge bounded by septa of Bertin on either side -DIF.DG - scars related to renal infarcts are typically situated between pyramids + focal nature / true renal scars are located overlying the medullary pyramids 4. SPLENORENAL FUSION -rare benign entity; to our knowledge, only six cases of developmental splenorenal fusion have been described in the literature -heterotopic splenic tissue in the renal capsule -CAUSES --developmental anomaly secondary to the fusion of nephrogenic mesoderm and splenic anlage in the second month of gestation --secondarily acquired as a result of splenosis after trauma or splenectomy -IMAGING --usually involves the left kidney, but its presence on the right side has also been documented --CT or gadolinium-enhanced MRI, splenorenal fusion appears as a solid enhancing mass arising from the kidney --99mTc sulfur colloid scan is confirmatory and shows uptake by the splenic tissue --biopsy or ferumoxides-enhanced MRI can help II. INFECTIOUS RENAL PSEUDOTUMORS 1. FOCAL PYELONEPHRITIS -renal infection confined to a single lobe -involving multiple lobes of the kidney is referred to as multifocal pyelonephritis - more common in patients with diabetes and those who are immunocompromised US -on sonography as either a hypoechoic or hyperechoic lesion in the renal cortex extending from the renal medulla to the renal capsule, with DECREASED PERFUSION on color-flow Doppler imaging -CEUS - uloga? CT -focal wedge- shaped area of low attenuation without a well- defined wall around it, and without an overlying bulge on the renal surface, which dis- tinguishes it from renal cell carcinoma -striations may also be observed in the nephrogram NUKL -99mTc-labeled glucoheptonate or dimercaptosuccinic acid (DMSA), is more sensitive and specific for focal pyelonephritis than any other imaging technique and shows a focal cortical defect in the kidney MEDULLARY RENAL CARCINOMA MAY HAVE AN APPEARANCE SIMILAR TO THAT OF FOCAL PYELONEPHRITIS!!! 2. RENAL ABSCESS -primarily caused by an ascending infection from the lower urinary tract with gram-negative bacilli and enteric bacteria, such as Escherichia coli, Klebsiella species, and Proteus species IMAGING -Sonography and CT reveal a well-defined heterogeneous mass -irregular walls with increased through-transmission on sonography and a low-attenuation lesion with enhancing walls on CT, along with a history of fever and a positive urinalysis and culture, indicate a renal abscess 3. SCARRED KIDNEY -severely scarred kidney secondary to infectious processes such as pyelonephritis or renal infarcts may also present as a potential pseudotumor on imaging -regions of preserved parenchyma may appear masslike on sonography or even in the nephrographic phase -appropriate corticomedullary differentiation in the early phases of enhancement on CT or MRI may be required to exclude a mass III. GRANULOMATOUS RENAL PSEUDOTUMORS 1.XANTHOGRANULOMATOUS PYELONEPHRITIS (XGP) -rare inflammatory condition usually secondary to chronic obstruction caused by nephrolithiasis and resulting in infection and irreversible destruction of the renal parenchyma -associated with a staghorn calculus in approximately 70% of cases -diabetes predisposes to the formation of XGP -XGP may rarely present with the classic urographic triad of unilaterally decreased or absent renal excretion, staghorn calculus, and diffuse renal enlargement -XGP may present in a dif- fuse or focal pattern --Focal or segmental XGP is more likely to mimic renal cell carcinoma US -single or multiple hypoechoic areas in the parenchyma of an enlarged kidney, with central echogenic foci representing calculi CT -low-attenuation areas (lipid-rich xanthogranulomatous tissue) and calcification in the mass -if calculi are not present, focal XGP with a low-attenuation area in the renal parenchyma may suggest a diagnosis of renal tumor 2. SARCOIDOSIS -more common in the African American population -Renal sarcoidosis can present in several ways: --most commonly as aberrant calcium metabolism, including hypercalcemia, hypercalciuria and nephrocalcinosis --granulomatous involvement of the kidney has been reported in 7-22% (autopsy) but radiographically distinct renal granulomas are rarely seen CT -multiple small (2-3 cm), low-attenuation nodular masses in the renal parenchyma that simulate renal lymphoma or metastasis -diffuse granulomatous infiltration of the kidney is a more rare radiologic finding than multiple nodules -granulomatous involvement of the kidney may also cause interstitial nephritis, which ap- pears as a striated nephrogram on contrast-en- hanced CT PET -increased 18F-FDG uptake by sarcoidosis, which, along with clinical information and the new radiotracers such as fluoro-α-methyltyrosine, may be helpful in distinguishing renal sarcoidosis from malignant disease of the kidney BIOPSY IS THE ONLY WAY TO CONFIRM THE DIAGNOSIS 3. MALAKOPLAKIA -rare inflammatory disorder related to defective macrophage function and is characterized by the deposition of soft, yellow- brown plaques in the kidney -there is usually an underlying urinary tract infection that results in the formation of plaques in the bladder and the kidney -malakoplakia may appear as an enlarged kidney, a low-attenuation mass, or a diffuse infiltrative disease - NONSPECIFIC -isolated renal malakoplakia without the presence of concurrent lower urinary tract --> MORE LIKELY TO BE TUMOR PHD -presence of Michaelis-Gutmann bodies is pathognomonic of malakoplakia IV. VASCULAR RENAL PSEUDOTUMORS 1. RAVM -congenital or acquired, with the most common cause being trauma -surgery, tumors, or idiopathic as other causes -RAVMs may be: --intraparenchymal --in the renal sinus and therefore may be difficult to distinguish from RCC and TCC on CT US -sonography can exclude the possibility of a solid mass by showing anechoic spaces in the lesion that fill with color on color-flow Doppler sonography MRI -internal flow voids in the lesion -abnormal tortuous vessels and an early draining vein characteristic of an AVM with Gd 2. SUBEPITHELIAL RENAL PELVIC HEMATOMA -also called Antopol- Goldman lesions -hematuria and flank pain -On CT, these hematomas appear as nonenhancing heterogeneously dense or hyperdense masses in the renal pelvis that may cause extrinsic luminal narrowing -BE CAREFUL!! - causes of many nephrectomies 3. EMH -occurs in three forms: --parenchymal - parenchymal type of renal involvement appears as a diffuse enlargement of the kidney or as either single or multiple small focal lesions --intrapelvic - either an extension of parenchymal involvement or is isolated --perirenal - single hypoattenuating mass or multiple nodules may be seen either around or completely encasing the kidneys -Biopsy confirmation is usually required in extramedullary hematopoiesis to help to differentiate it from lymphoma or urothelial tumors KEY - POVEZANO S HEMATOLOŠKIM BOLESTIMA - most common in myelofibrosis with myeloid metaplasia -chronic myeloproliferative disorder -polycythemia vera -essential thrombocytosis V. OSTALA STANJA -crossed fused renal ectopia -renal tuberculosis -anticoagulant-induced subcapsular hemorrhage -regenerating nodule after reflux

SUMMA SUMMARUM FOLLOW UP-a

Imaging in the Follow-Up of Renal Cell Carcinoma, AJR 2012.

PUTEVI METASTAZIRANJA RCC-a

RCC metastasizes in two basic ways: --hematogenous and lymphatic dissemination --RCC has a tendency to invade the venous system --venous extension has been observed in 20%-35% of patients with RCC at presentation --tumor thrombus in the renal vein may spread into the inferior vena cava and extend into the right chambers of the heart --> tumor cells reach the lungs as a first step in the metastatic cascade and, after that, the systemic circulation --important vessels that drain into the renal vein on the left side and into the inferior vena cava on the right side (mainly the adrenal, gonadal, and second lumbar veins) --> blood reflux to those veins can account for the spread of RCC to uncommon organs, such as the ovaries or testicles, or to the adrenal glands, as well as for the fact that ovarian metastases from RCC are usually unilateral, unlike ovarian metastases that arise from other tumors --complex relationship between the perirenal plexuses and other plexuses (eg, the retroperitoneal and paravertebral Batson plexuses), which represent alternative routes of disease dissemination, favored by the presence of thrombosis, which would explain the uncommon sites of RCC metastases, such as the retroperitoneal space, colon, and pelvis --metastatic lesions usually enhance to the same or similar degree as the primary tumor --metastases from clear cell RCC enhance to a degree similar to that seen in the renal cortex in the arterial phase --metastases from non-clear cell RCCs enhance to a lesser degree --some metastases, especially those from clear cell RCC, are detected only during the arterial phase of the study --hypovascular metastases are best detected during the nephrographic phase

STAGING RCC-a

T T1 T1a: tumor confined to kidney, <4 cm T1b: ltumour confined to kidney, >4 cm but <7 cm T2: limited to kidney >7 cm T2a: tumor confined to kidney, >7 cm but not >10 cm T2b: tumor confined to kidney, >10 cm T3: tumor extension into major veins or perinephric tissues, but not into ipsilateral adrenal gland or beyond Gerota's fascia T3a: Tumor grossly extends into the renal vein or its segmental (muscle-containing) branches, or tumor invades perirenal and/or renal sinus fat but not beyond the Gerota fascia T3b: spread to infra diaphragmatic IVC T3c: spread to supra diaphragmatic IVC or invades the wall of the IVC T4: involves ipsilateral adrenal gland or invades beyond Gerota's fascia N N0: no nodal involvement N1: metastatic involvement of regional lymph node(s) M M0: no distant metastases M1: distant metastases stage I: T1 N0 M0 stage II: T2 N0 M0 stage III: T3 or N1 with M0 stage IV: T4 or M1 BITNO --regional lymph nodes (N) in RCC are the hilar and retroperitoneal (paraaortic and paracaval) nodes --remaining lymph nodes (mediastinal, pelvic, and inguinal) are considered M1 --complex relationship between perirenal venous plexuses and retroperitoneal venous plexuses accounts for some uncommon metastatic sites --two of the routes through the perirenal veins: ---one drains directly into the portal vein through the colic veins, thus explaining why some patients have liver metastases in the absence of lung metastases ---in the second route, the perirenal plexuses communicate with gonadal vessels --PROBLEM RAZLIKOVANJA IZMEĐU T2 I T3a (most specific finding of stage T3a disease, the presence of an enhancing nodule in the perinephric space, is highly specific but only 46% sensitive) ---T2 and T3a tumors is problematic ---perinephric stranding does not reliably indicate tumoral spread and is found in about half of patients with localized T1 and T2 tumors ----perinephric stranding may be caused by edema, vascular engorgement, or previous inflammation --this limitation of CT does have prognostic implications BUT DOES NOT AFFECT CASE MANAGEMENT, since patients with stage T3a disease are candidates for radical nephrectomy or nephron-sparing nephrectomy

TRANSPARENCHYMAL RENAL PROPAGATION OF RCC AND RENAL VEIN THROMBOSIS - image

Transparenchymal renal propagation of cancer and renal vein thrombosis resulting in a non-functioning kidney. Drawing illustrates intrarenal propagation of a lower-pole RCC to the upper pole. Note the presence of "tumor vessels" within the renal vein thrombus, invasion of the IVC, and extensive collateral venous circulation.

ATRAUMATSKA KRVARENJA IZ BUBREGA - DIF.DG.

atraumatic renal and perirenal hemorrhage can occur secondary to: 1. benign renal tumors 2. vasculitis 3. aneurysm 4. systemic anticoagulation 5. infection 6. nephritis 7. malignant renal neoplasms