Genitourinary

Epididymitis / Epididymo-orchitis

- almost always ascending from the urinary tract > epididymis > teste - clinical presentation = acute unilateral scrotal pain - infection and secondary inflammation can cause venous hypertension, which is a risk factor for focal testicular ischemia. Imaging (US): - enlarged epididymis / teste with increased color Doppler flow relative to the testicle - hydrocele may be present, which often contains low-level echoes. Ddx = testicular torsion (decreased testicular blood flow)

Ureteritis cystica

- benign response to chronic urinary tract inflammation, such as chronic infection or stone disease. No malignant potential. - same disease entity can affect the renal pelvis (called pyelitis cystica) and bladder (called cystitis cystica). - several small subepithelial cysts can be found unilaterally in the proximal third of the ureter and renal pelvis Imaging: - multiple tiny filling defects in the ureter

Bladder TCC / urothelial cell carcinoma

- by far the most common bladder cancer - presents as painless hematuria, more commonly seen in older males with risk factors such as smoking and aromatic amines. -bladder cancer spreads through the wallof the bladder. Organ-confined disease canbe divided into non-muscle-invasive (70%; typically resected endoscopically) and muscle- invasive (25%; typically treated with radical cystectomy/nodal dissection). Metastatic bladder cancer (5%) is treated with systemic therapy.

Prostatitis

- can be acute or chronic - can be diffuse or focal (typically peripheral zones) - fluctuating PSA levels or reducing PSA with antibiotics - aetiology: prostate reflux, infected urine, or instrumentation MRI: - T2 hypointense signal and mild-moderate

ovarian hyperstimulation syndrome (OHSS)

- complication of infertility treatment, thought to be due to vascular endothelial growth factor (VEGF) dysregulation causing capillary leak - diagnostic criteria = abdominal pain, bilateral and symmetric spoke- wheel enlargement of the ovaries (>5 cm), and presence of either ascites or hydrothorax. - at least one additional laboratory or clinical symptom must be met, including elevated hematocrit (≥45%), elevated WBC (>15,000), elevated LFTs, acute renal failure, or dyspnea. - increases the risk of ovarian torsion and ectopic pregnancy, and it can lead to coagulopathy, hypovolemia, and shock.

Ureterocele

- focal dilation of the most distal portion of the ureter which protrudes into the bladder (cobra head sign). An ureterocele may be orthotopic or ectopic. An orthotopic ureterocele is seen with a normally inserting ureter, and is seen most commonly in adults. Orthotopic ureteroceles are also known as simple, adult-type, and intravesicular ureteroceles. Orthotopic ureteroceles are usually asymptomatic. An ectopic ureterocele is seen in the setting of a duplicated collecting system, with ectopic insertion of the upper pole ureter into the bladder (Weigert-Meyer rule), and is usually diagnosed in children. A pseudoureterocele represents intussusception of the distal ureter into the bladder, which may be due to tumor, radiation cystitis, or vesicoureteral junction stone.

Medullary sponge kidney

- idiopathic ectasia of the renal tubules, resulting in urinary stasis and stone formation - most cases are noted incidentally, but patients may suffer from recurrent urolithiasis or pyelonephritis - usually bilateral and segmental with sparing of a portion of the renal pyramids Imaging: - on plain radiographs or computed tomography, macro- scopic chunky calcifications will be noted along the renal pyramids - Classic findings on intravenous pyelogram (IVP) include the "growing calculus" sign secondary to contrast filling the dilated tubules around the stones, and the striated, "paintbrush" appearance of the renal pyramids - associated with hemihypertrophy syndromes.

Ovarian neoplasms

- includes a large group of benign and malignant tumours that can be classified based on where they originate in the ovary. - 80% of ovarian masses are benign. - three histologic types of primary ovarian neoplasm include: - epithelial neoplasm - germ cell tumor - sex cord-stromal tumor Surface epithelial tumors account for 70% of ovarian neoplasms overall and >90% of ovarian cancers Germ cell tumors include mature cystic teratomas (dermoid) and dysgerminomas. Struma ovarii is a subtype of teratoma that is composed of mature, functioning thyroid tissue Sex cord-stromal tumors include fibroma, thecoma, and fibrothecoma Meigs syndrome is the triad of benign ovarian fibroma, ascites, and right pleural effusion. Tumors containing thecal cells produce estrogen and may cause endometrial carcinoma. O-RADS

Utricle cyst

- midline cystic structure within the prostate usually located posterior to the urethra - freely communicates with urethra - results in post-void dribbling - remnant of Mullein duct system - associated with hypospadias - diagnosed in younger patients (10-20) c.f. Mullein duct cysts which occur in older patients (30-40) and are found anywhere along from scrotum to utricle US: - cystic structure posterior to prostate MRI: - high T2 signal but variable if haemorrhage or infected

polycystic ovarian syndrome

- polycystic ovarian syndrome is a clinical syndrome of obesity, insulin resistance, anovulation, and hirsutism secondary to excess androgens Imaging: - US criteria include = >12-20 small follicles (most often arranged around the periphery of the ovary), none greater than 9 mm in diameter, and an ovarian volume >10 mL - ovarian stroma is typically very vascular when evaluated by color Doppler. Differential: - normal ovaries under the influence of OCP although contraceptives will not increase the vascularity of the ovary.

Penile carcinoma

- rare - >95% SCC - typically occurs at the glans - usually spreads via lymphatics as Buck's fascia prevents spread to corpora or haematogenously

Adenoma malignum

- rare subtype of well-differentiated mucinous adenocarcinoma of the cervix - unfavourable prognosis due to peritoneal dissemination in early stage and poor response to radiation and chemotherapy Imaging: - multicystic mass (cluster of cysts) with solid components that extends from the endocervical glands to deep cervical stroma - associations with Peutz-Jeghers syndrome and mucinous ovarian neoplasms have been reported

Leukoplakia / squamous metaplasia

- rare urothelial inflammatory condition named for the characteristic white patch that it produces. not premalignant when the renal collecting system is involved, although there is an association between squamous cell carcinoma and bladder leukoplakia. Imaging shows a flat mass or focal thickening of the renal pelvic or ureteral wall that may produce a characteristic corduroy appearance.

Vaginal fistulas

Anovaginal fistula can arise from Crohn's disease, obstetric trauma, pelvic floor surgery, and radiation therapy. Gas and feces passed through the vagina can cause recurrent vaginal infections. Urethrovaginal fistula can occur after excision for urethral diverticulum, resulting in urinary incontinence. Vesicovaginal fistula represents a significant morbidity in female urology and occurs most commonly in the setting of obstructed childbirth or after urologic or pelvic surgery. On MRI imaging, sagittal plane is the most reliable plane for visualization of fistulas. Real-time fluoroscopic evaluation can be useful tools to characterize fistulas. Depending on location and organs involved, contrast can be injected into the relevant space to assess for abnormal extravasation.

Bladder trauma

Imaging = cystogram Extra-peritoneal bladder rupture: - at least twice as common as intraperitoneal rupture - more commonly associated with pelvic fractures compared to intraperitoneal rupture (direct laceration by bone fragment) - molar tooth sign (see picture) - managed conservatively by placement of catheter Intra-peritoneal bladder rupture: - disruption of bladder dome and peritoneum - mechanism = pressure forces on a full bladder > bursting at the dome - pathognomonic imaging finding = intraperitoneal contrast between loops of bowel on cystogram - requires surgical management

Endometritis

Imaging: - essentially normal postpartum appearances in uncomplicated cases - gas in the uterus >3 weeks post delivery is suspicious for endometritis, though can be normal <3 weeks

Adrenal cyst

Imaging: - thin non enhancing wall - fluid filled - posterior enhancement on US Aetiology - endothelial = 45% - pseudocyst = secondary to haemorrhage (39%), may have peripheral calcs - epithelial cyst = rare (9%) - hydratid = very rare (internal membrane) May occasionally be complex and confused with cystic or necrotic neoplasm > biopsy

Pyonephrosis / pus under pressure

Infection of an obstructed collecting system Treatment is emergent relief of obstruction, either with percutaneous nephrostomy or ureteral stent. Ultrasound shows nonshadowing echogenic material within a dilated collecting system. A fluid-fluid level may be present.

Pyelonephritis

Infection usually ascends from the bladder Imaging: - 75% of the time normal - unilateral kidney enlargement - wedge-shaped or striated regions of decreased enhancement - perinephric stranding - urothelium may be thickened and hyperenhancing. Lobar nephronia / focal pyelonephritis - can mimic a renal mass. - US = hypoechoic mass (or masses) with low-amplitude echoes that disrupts the corticomedullary junction - distinct wall is lacking - mild hydronephrosis can be seen on the affected side, thought to be due to a bacterial endotoxin causing reduced peristalsis, and should not be confused with obstructive uropathy Emphysematous pyleonephritis - replacement of renal parenchyma with gas - complication of acute pyelonephritis - most commonly by E. coli - almost exclusively in diabetes mellitus or immunocompromised individuals - surgical emergency - US = high amplitude echoes in parenchyma representing gas locals without posterior shadowing

Adrenal metastasis

Lung and melanoma are most common washout studies can determines Precontrast attenuation of more than 43 HU in a noncalcified, nonhemorrhagic lesion is suspicious for malignancy, regardless of washout characteristics.

Multiple bilateral renal lesions/masses Ddx

Lymphoma Lobar nephronia (infection) RCC (von Hippel-Lindau)

Malacoplakia

Malacoplakia (soft plaque) is a rare chronic inflammatory granulomatous condition associated with chronic urinary tract infection (usually Escherichia coli) that is typically seen in middle-age women. It is not premalignant. The bladder is the most frequently involved organ, followed by the renal parenchyma, upper urinary tract, and urethra. Imaging shows multiple flat filling defects that characteristically involve the distal ureter and/or bladder.

Renal papillary necrosis

Necrosis and sloughing off of renal papillary tissue Aetiology: Pyleonephritis Obstruction Sickle cell TB Cirrhosis Analgesia (NSAIDs) Renal vein thrombosis Diabetes mellitus Imaging: - focal areas of increased echogenicity - pooling of contrast in the papillary regions adjacent to the calyces - filling defects within the contrast = sloughed papilla - calyces may appear club shaped or saccular - ball on tee sign = contrast filling a central papilla - signet ring sign = contrast filling around a sloughed papilla

Renal trauma

Organ injury scale (OIS) Grades: 1 = (95%) renal contusion or sub capsular haematoma 2 = superficial laceration (<1cm) or perinephric haematoma confined to Gerota's fascia without urinary extravasation 3 = deep laceration (>1cm) without urinary extravasation, bleeding contained to Gerota's fascia 4 = deep laceration which extends into the collecting system (causing urinary extravasation), renal pelvis laceration or complete disruption of the ureteropelvic junction, segmental renal artery/vein injury, vascular thrombosis resulting in segmental or complete kidney infarction, or active bleeding beyond Gerota's fascia. Vascular grade IV injury can be treated with endovascular embolization or stenting. 5 = most severe injury and includes main renal artery/vein laceration or avulsion of the renal hilum, devascularized kidney with active bleeding, or shattered kidney. Treatment is variable but typically surgical. Renal artery pseudo aneurysm / AV fistula - both appear on imaging as hyper attenuating focus with density similar to aorta that decreases on delayed phase imaging - contrasts to active bleeding which increase in attenuation / size with delayed phase imaging

Pheochromocytoma

Pathophysiology: - intra-adrenal paraganglioma - neuroendocrine tumour that typically originates in the medulla - composed of chromataffin cells > secrete catecholamines > 2* HTN, headaches, and diaphoresis - approximately 90% are benign Imaging: - can be large and heterogeneous due to areas of necrosis, hemorrhage, and occasionally calcification - CT = avid enhancement - MRI = marked T2 hyperintensity (light bulb sign) and avid enhancement with variable washout kinetics Associations: - Multiple endocrine neoplasia (MEN) - von Hippel-Lindau - NF type 1 - Carney's triad - Hereditary paraganglioma-pheochromocytoma syndrome Notes: - most common site of an extra-adrenal paraganglioma is the organ of Zuckerkandl, located along the aortic bifurcation to the level of the bladder. Although rare, when the bladder is involved, it can produce a distinctive clinical presentation of post-micturition syncope (syncope after urination) -Paragangliomas of the head and neck are generally called glomus tumors and may be associated with the tympanic membrane (glomus tympanicum), the jugular foramen (glomus jugulare), the carotid body (called a carotid body tumor), or the vagus nerve (glomus vagale)

Testicular rupture

rupture causes capsule disruption, often with protrusion of testicular parenchyma through the defect. Rupture is often associated with a testicular hematoma or contusion. Prompt diagnosis is critical, as testicular viability is dependent upon timely repacking of the seminiferous tubules back inside the capsule. Testicular rupture results in disruption of the blood-testis barrier and may be associated with future infertility due to the formation of anti-spermatozoa antibodies.

Penile fracture

rupture of the corpus cavernosum (usually unilateral) as a result of trauma to the erect penis cracking sensation > extreme pain > rapid swelling surgical repair required US or MRI

Testicular torsion

twisting of the testicle around the spermatic cord and vascular pedicle > infarction > necrosis De-torsion in <6 hours = excellent outcome De-torsion after 24 hours = unsalvageable Risk factor = bell-clapper deformity (small testicular bare area i.e. attachment site which prevents rotation) Ultrasound findings: - hyper acute = hyper echoic and shadowing torsion knot of twisted epididymus and spermatic cord with no blood flow to the teste - acute = teste is enlarged and heterogenous - missed torsion (>24 hours) = enlarged and mottled teste with scrotal thickening and increased flow in the scrotal wall. - complex or separated hydrocele may be present

Idiopathic adrenal haemorrhage

usually unilateral > hypo function

Adrenal cortical carcinoma

very rare 65% are functional > array of hormones Imaging: Internal necrosis and haemorrhage are typical features

dermoid cyst aka mature cystic teratoma

Pathophysiology: - most common ovarian neoplasm - technically, a teratoma contains all three primitive germ cell layers, while a dermoid cyst may contain only two. In general use, however, these terms are interchangeable. Complications: - malignant transformation is very rare and typically occurs in postmenopausal patients - intraperitoneal rupture leading to acute peritonitis - can act as a lead point for adnexal torsion particularly when large (>4 cm) Imaging: - complex ovarian cyst with an echogenic Rokitansky nodule, which is a solid nodule projecting into the cyst cavity, from which hair or teeth may arise - dot-dash pattern describes interrupted echogenic lines thought to be produced by keratin fibers - tip of the iceberg sign describes obscuration of the deeper contents due to high-attenuation material - fat containing soft tissue mass - CT and MRI = heterogeneous unilocular cystic structure with coarse calcification, corresponding to sebaceous material, hair follicles, and fat - Rokitansky nodule may or may not be seen. - less commonly, a dermoid cyst may appear as a solid hyperdense or fat-density mass. - endometriomas and teratomas are predominantly hyperintense on T1-weighted images due to their blood and fat content, respectively. Distinction can be made by using the fat-suppressed imaging sequences. Teratoma will show signal loss on the fat-suppressed images, due to internal macroscopic fat, while an endometrioma will not.

Adrenal hyperplasia

Pathophysiology: - prolonged stress or ectopic ACTH secretion

Adnexal torsion

Pathophysiology: - twisting of the ovarian vascular pedicle > pain and potential vascular compromise to the ovary - ovaries have dual blood supply (ovarian A. and uterine A.) so may still have arterial flow - may be intermittent - mainly reproductive-age women, and commonly occurs in pregnancy - more commonly on the right side due to the position of the sigmoid colon, which inhibits free rotation of the left adnexa - lead-point adnexal mass may predispose, particularly if large, most commonly an ovarian dermoid Imaging: - enlarged, edematous ovary with abnormal Doppler, and free fluid. - twisting ("swirling") of the vascular pedicle (whirlpool sign) is very specific, but not often seen - unusual position of affected ovary - free fluid - peripheral displacement of follicles due to central haemorrhage and oedema - because of the dual blood supply to the ovary (lateral from the ovarian vessels off the aorta, and medial from the uterine vessels from the internal iliac), flow may still be detectable by colour Doppler, even with torsion - intermittent ovarian torsion and detorsion may also explain detectable color Doppler flow in these cases.

Oncocytoma

Pathophysiology: benign renal tumor arising from tubular cells. Due to significant imaging overlap with RCC, oncocytomas are usually biopsied or surgically resected. Imaging: - US = indistinguishable from RCC. It has variable echogenicity. A spoke-wheel vascular pattern is sometimes seen on color Doppler. - CT/MRI = certain features can suggest oncocytoma, but cannot reliably differentiate it from RCC. Features suggestive of oncocytoma include homogeneous enhancement and a central scar. The segmental enhancement inversion sign can be a more specific feature, referring to a "flip-flop" of enhancement of the tumor and central scar on early and late phases.

Retrograde urethrogram

Perform if blood at tip of urethra in trauma before placing catheter (suprapubic instead of foley if urethral injury) Retrograde urethrogram (RUG) provides excellent evaluation of the anterior urethra and may be performed to evaluate for suspected urethral injury, stricture, or fistula. To perform a RUG, the fossa navicularis is cannulated with a sterile balloon-tipped catheter that is inflated with 1-2 mL saline. Subsequently, approximately 10 mL of contrast is hand- injected under fluoroscopy.

Zones of the prostate

Peripheral zone (70% of adenocarcinoma here) Central zone (prostate is mostly central zone in young men) Transitional zone (enlarges in BPH > central gland replaced) Anterior fibromuscular stroma

Solid renal mass Ddx

RCC Oncocytoma AML ---------------------------------- TCC Lymphoma

Page Kidney

Rare cause of secondary HTN due to extrinsic compression by a sub-capsular collection (haematoma / urinoma) usually following trauma Subcapsular collection compresses the renal parenchyma and decreases its blood flow > altered hemodynamics induce increased renin secretion > HTN It usually takes several months for hypertension to develop. Percutaneous drainage of the hematoma may be effective treatment. Imaging: - subcapsular hematoma causing deformation and flattening of the kidney.

Adrenal hypofunction

Requires substantial destruction of adrenal tissue Addisons disease - chronic adrenocortical insufficiency Aetiology = autoimmune destruction of adrenal or prior infection

Retroperitoneal mass Ddx

Retroperitoneal haemorrhage Lypmhadenopathy Retroperitoneal abscess ------------------------------- Retroperitoneal fibrosis Retroperitoneal sarcoma (liposarcoma most common type)

Bladder stones

Risk factors for bladder stones include urinary stasis (most often bladder outlet obstruction) and chronic inflammation (e.g., from infection or foreign body). An off-midline bladder stone should raise concern for a bladder mass or enlarged prostate which displaces the bladder stone, or a stone within a ureterocele or a bladder diverticulum

Benign vaginal retention cysts

Skene duct cysts (paraurethral duct cyst): Retention cysts due to obstruction or inflammation ofthe paraurethral ducts. They are typically located anterior, near midline and below the level of pubic symphysis. MRI shows T2 hyperintense signal if uncomplicated, but hemorrhage may cause fluid-fluid levels. Gartner duct cysts: Retention cysts arising from the embryologic remnants of the mesonephric (Wolffian) duct. They are found in the anterolateral vaginal wall, above the level of pubic symphysis. MRI and US often detect Gartner duct cysts incidentally. Bartholin gland cysts: Retention cysts due to obstruction of the Bartholin duct by prior infection or trauma resulting in stenosis, stone, or thick mucus and retained secretions. They are found in the inferior third of the vagina at the posterolateral vaginal wall, below the level of pubic symphysis and associated with the labia majora. Superinfection of the cysts may occur. MRI signal characteristics depend on protein content of the cyst resulting in variable T1 and heterogeneous T2 signal. Nabothian cysts are located at the cervix and are due to occlusion of cervical glands.

Uretal filling defect Ddx

TCC Polyp Clot sloughed papilla leukoplakia / malacoplakia

Uterine AVM

Trivia: - abnormal communication between the uterine arterial branches and draining myometrial venous plexus - may be congenital (very rare) or acquired (post-traumatic, infection, or iatrogenic, such as post dilation and curettage (D&C)) Imaging: - grayscale and color Doppler can show an enlarged, heterogeneous, and multicystic- appearing uterus - he appearance is similar to gestational trophoblastic disease (discussed in the first trimester of pregnancy section), but with negative β-hCG

Endometrial hyperplasia

Trivia: - abnormal proliferation of the endometrial glands and stroma - can be seen in all age groups - typically presents as abnormal uterine bleeding Pathophysiology: - occurs due to unopposed estrogen stimulation, and can have various causes (obesity, polycystic ovary syndrome, pregnancy, estrogen-secreting ovarian tumors, and tamoxifen). Imaging: - nonspecific including smooth endometrial thickening and/or cystic changes - hyperplasia, metaplasia, or carcinoma cannot be reliably distinguished by imaging. - in premenopausal women, evaluation is based on clinical symptoms, in particular, abnormal uterine bleeding (endometrial thickness varies with the menstrual cycle and is a poor predictor for endometrial pathology) - in post-menopausal women = > 5 mm thickness or 8 mm on HRT

Female urethral diverticulum

Trivia: - presents with post-void dribbling, urethral pain, and dyspareunia, or may be vague and nonspecific - very rarely, adenocarcinoma may develop within a urethral diverticulum Pathophysiology: - thought to arise from glandular dilation caused by inflammation and chronic infection of the paraurethral glands of Skene Imaging: - urethral diverticulum appears as a periurethral cystic lesion that typically arises from the posterolateral urethra and wraps around the urethra circumferentially with a classic saddlebag or U-shaped morphology - prone to develop calculi due to urinary stasis.

Retroperitoneal fibrosis

Trivia: - rare inflammatory disorder associated with fibrosis deposition in the retroperitoneum > ureteral obstruction - unlike retroperitoneal lymphadenopathy it rarely displaces the aorta from the spine

Cervical carcinoma

Trivia: - third most common gynecologic malignancy (decline due to screening with Pap smears) Imaging: - US = hypoechoic or isoechoic soft tissue mass involving the cervix with/ without intratumoral necrosis - endometrial cavity may be distended by fluid or blood products due to cervical obstruction - MRI = T2 intermediate to hyperintense signal mass replacing the normally T2 hypointense cervical stroma. Enhancement is variable on postcontrast images. Staging: - a cervical mass >1.5 cm should be evaluated by MRI for staging - cervical stroma is the key landmark in the staging of cervical cancer: If tumor extends through the cervical stroma into the parametrium, the cancer is stage IIB and treatment is typically non-surgical ("IIB or not IIB"). - other key findings to note are involvement of bladder or rectum, which denotes stage IV disease (if shown to extend to the mucosal surface with cystoscopy or endoscopy). - based on the FIGO (International Federation of Gynecology and Obstetrics) system, which characterizes extent of disease based on involvement of the uterus, vagina (upper 2/3 versus lower 1/3), parametrium, pelvic sidewall, adjacent bladder and rectum, pelvic lymph nodes, and/or distant metastases.

Syndromes with renal masses

von Hippel-Lindau (VHL) - autosomal dominant multi-organ syndrome caused by a mutation in the VHL tumor suppressor gene on chromosome 3, which leads to cysts and neoplasms in multiple organs. - primary manifestation of VHL in the genitourinary system is multiple bilateral renal cell carcinomas, most commonly the clear cell subtype. - other genitourinary manifestations of VHL include multifocal pheochromocytoma and renal cysts. - central nervous system manifestations of VHL include hemangioblastoma of the brainstem, cerebellum, or spinal cord. - pancreatic and hepatic manifestations include malignant neuroendocrine pancreatic tumor, pancreatic serous cystadenoma (a benign neoplasm), and pancreatic/hepatic cysts. Birt-Hogg-Dubé - autosomal dominant syndrome (mutation of BHD gene on chromosome 17p) of dermatologic lesions, cystic lung disease, and multiple renal oncocytomas, renal cell carcinomas (chromophobe subtype), and hybrid chromophobe RCC- oncocytoma tumors. Tuberous sclerosis (TS) - autosomal dominant neurocutaneous disease caused by a tumor suppressor gene mutation. It manifests clinically with seizures, developmental delay, and (mostly) benign tumors in multiple organ systems. - most common renal manifestation of TS is multiple bilateral renal angiomyolipomas (AMLs). Approximately 50% of patients with TS will have at least one AML. - Renal cysts can be seen in ~25%. - The relative risk of renal cell carcinoma is increased in patients with TS, which occurs in approximately 2-3% of patients. Diagnosis of renal cell carcinoma is complicated by the abnormal kidneys that may have multiple cysts and/or AMLs. - Heart = the most common neoplasm is a rhabdomyoma. A cardiac rhabdomyoma may be present during fetal life and can be detected by fetal ultrasound. - Lung = a process of smooth muscle proliferation identical to lymphangioleiomyomatosis can occur, causing cystic replacement of lung parenchyma. It has been suggested that the abnormal smooth muscle in the lung in patients with TS represents genetically identical metastatic smooth muscle from a renal angiomyolipoma. Hereditary papillary RCC (HPRCC) • HPRCC is an autosomal dominant syndrome that presents with multiple, bilateral papillary RCCs. It is associated with mutations in the MET gene. Hereditary leiomyomatosis and RCC (HLRCC) - HLRCC is an autosomal hereditary syndrome characterized by the development of multiple RCCs, uterine and cutaneous leiomyomas, and adrenal hyperplasia. The most commonly seen renal cancer subtype is papillary RCC. Sickle cell trait Sickle cell is associated with medullary renal carcinoma.

Bengin testicular tumours:

Epidermoid Sex cord-stromal tumours Sarcoidosis mimics = congenital adrenal rests, supra-numerary testis

Epidermoid

Epidermoid = keratin-filled cyst Findings: - distinctive onion skin appearance of concentric alternating rings of hypo- and hyperechogenicity Management: - local excision instead of the standard orchiectomy typically performed for presumed malignant masses

Retroperitoneal anatomy

Fascia: - parietal peritoneum - anterior para-renal fascia - posterior para-renal fascia - lateroconal fascia Spaces: Anterior pararenal fascia - ascending and descending colon - pancreas - 2nd part of duodenum Perirenal space - adrenals - kidneys / proximal ureters - fat Posterior pararenal fascia - fat

Benign ureteral masses

Fibroepithelial polyp • Fibroepithelial polyp is the most common benign tumor of the ureter. It typically affects the proximal ureter. Fibroepithelial polyp features a long stalk and can be large. They usually appear as an elongated smooth tubular lesion. CTU best shows the lesion on the coronal images in the excretory phase. Transurethral excision is the treatment of choice. Urothelial papilloma • Urothelial papilloma is a rare benign neoplasm that may involve the bladder or ureter. The mass may become quite large and mimic a malignancy. Inverted papilloma • Inverted papilloma is a benign mass with a central core of urothelium.

Functional ovarian cysts

Functional cysts include follicular cysts, corpus luteal cysts, and theca lutein cysts Follicular cyst (usually called a simple cyst), results from failed ovulation of the dominant follicle(s). The dominant follicle continues to grow in size and is considered a follicular cyst when >3 cm A corpus luteal cyst results from failed involution of the corpus luteum. Like the follicular cyst, it can continue to grow in size and must be >3 cm for diagnosis. A corpus luteal cyst can have variable appearances, but will often look like a complex ovarian cyst. High diastolic flow is often present, which can also be seen in ovarian cancer. Theca lutein cysts are often multiple and arise from elevated hCG. They can be seen in molar pregnancy, multiple gestations, or infertility patients on gonadotropins or clomiphene. A hemorrhagic cyst is most often the result of hemorrhage into a functional cyst, most commonly a corpus luteum. Ultrasound findings can be suggestive, although a complex cyst should be followed-up at least once to ensure resolution O-RADS CRITERIA:

Renal pseudotumours (normal variants)

Hypertrophied column of Bertin - structure anchoring the cortex to the hilum / separate pyramids Persistent fetal lobulation Dromedary hump

Lithium nephropathy

presents as diabetes insipidus or CKD Imaging: - umerous scattered uniform microcysts in bilateral normal-sized kidneys - US = cysts appear as punctate echogenic foci. - CT may show calcification within the cysts

Renal lymphoma

primary is rare and of uncertain origin as there is no native lymphoid tissue in the kidneys

Bladder adenocarcinoma

rare associated with persistent urachal remnant

Renal collecting duct carcinoma

rare similar to medullary carcinoma

Adrenal lymphoma

rare but suspected if lymphadenopathy and splenomegaly

Renal cortical necrosis

resulting from ischaemia due to small vessel vasospasm or systemic hypotension predisposing factors: - haemolytic uraemia syndrome - thrombotic microangiopathy imaging: - lack of enhancement of the cortex

Adrenal haemorrhage

Aetiology: - usually anticoagulation or malignancy Imaging: - can look mass like - often heterogenous - does not enhance on post-contrast imaging - rapid onset - interval decrease in size on follow up imaging

Renal anomalies

Horseshoe = 2 kidneys connected anteriorly across the midline Crossed fused renal ectopia = 2 kidneys located on the same side and at least partially fused with normal insertion of ureters into bladder Unilateral renal agenesis = single hypertrophied kiney Supranumery kidneys Duplicated collecting system / Duplex kidney = upper and lower moieties are drained by separate ureters - upper pole ureter has an ectopic ureter into the bladder + often associated with uretocele / obstruction - lower pole ureter has normal insertion into the bladder + often associated with reflux

Sex cord stromal tumors

90% benign Findings: - sonographically indistinguishable from a malignant tumour Management: - orchiectomy Types: - Lydia cell tumour = gynaecomastia due to oestrogen secretion - Sertoli cell tumour = associated with Peutz-Jeghers and Klinefelter syndrome

Prostate cancer

90% occur in the peripheral zone Gleason scale (histology) Staging: TNM PI-RADS:

Focally increased kidney echogenicity

AML Calculus Milk of calcium Sloughed papilla (due to papillary necrosis) Intra-renal gas Atypical malignant neoplasm

Retroperitoneal haematoma

Aetiology: - anticoagulation - trauma - ruptured AAA - renal mass e.g. AML - iatrogenic e.g. femoral vascular access non-con > arterial

Testicular mets

Aetiology: - most common = leukaemia and lymphoma - chemotherapy for above does not cross blood-testis barrier Findings: - older patients - bilateral - may be infiltrative with diffuse testicular enlargement

Polycystic Kidneys

Autosomal dominant polycystic kidney disease (ADPKD): - bilaterally enlarged kidneys with multiple large renal cysts. - progressive renal failure - present in their third to fourth decades - may display secondary hypertension and hematuria (nephrolithiasis vs. rupture of a renal cyst into the collecting system) - pproximately 70% of patients have multiple hepatic cysts - 15% of patients have saccular cerebral aneurysms - not known to increase caner risk - RCC associated with ADPCKD occurs earlier, multifocal, and bilateral Imaging: - kidneys are markedly enlarged and feature multiple cysts of varying attenuation (or signal intensity on MRI) due to haemorrhage Autosomal recessive polycystic kidney disease (ARPKD) - enlarged kidneys with innumerable tiny renal cysts. - diagnosis of infancy and has a poor prognosis. - If the child survives infancy, hepatic fibrosis usually develops. - ARPKD presents in utero as enlarged echogenic kidneys (the cysts are too small to be individually resolved by ultrasound) Acquired cystic kidney disease (due to end-stage kidney disease) - patients on long-term dialysis often develop many small renal cysts superimposed upon atrophic kidneys. - dialysis-associated cystic renal disease portends an increased risk of renal cell carcinoma (~2-3% prevalence, compared to 1/10,000 prevalence in the general population) Localized cystic renal disease - benign, slowly progressive proliferation of cysts, typically within a normal functioning kidney and asymptomatic - always unilateral, and usually affects only part of the kidney. No imaging follow-up or treatment required.

Post caesarean-section haematoma

Bladder-flap hematoma is a rare complication of a low-transverse Caesarean section, where a postsurgical hematoma forms in the vesicouterine space (between the posterior bladder and the anterior uterus). Ultrasound of a bladder-flap hematoma will show a complex mass posterior to the bladder. Subfascial hematoma is also a rare complication of Caesarean section due to extraperitoneal hemorrhage within the prevesical space (anterior to the bladder). Ultrasound shows a complex mass anterior to the bladder.

Renal calculi

Composition: - 73% are calcium-containing (radio-opaque) - calcium oxalate, calcium phosphate or both - Non calcium-containing = uric acid, xanthine, struvite, HIV retroviral therapy (indinavir) Imaging: - soft tissue rim sign = presence of a small amount of soft tissue surrounding the calcification, thought to represent the edematous ureteral wall - ipsilateral hydronephrosis and stranding - US = echogenic focus + twinkling artefact - Resistive index high - ureteric jets absent

Adrenal hyperfunction

Cushing syndrome - excess cortisol - aetiology = Cushing disease i.e. pituitary - aetiology = non pituitary i.e. idiopathic adrenal hyperplasia, adrenal adenoma, ectopic para-neoplastic ACTH Conn syndrome - excess aldosterone - results in hypokalaemia and HTN - aetiology = usually an adenoma that is small and difficult to detect on CT

Normal cyclical

Day 5-7 = multiple Graafian follicles become apparent in the ovary (these are <3 cm in diameter). Day 8-13 = one (or more) dominant follicles arise. Day 14 = Ovulation. Physiologic bleeding occurs into the follicle at the time of ovulation, at which point the follicle is called the corpus hemorrhagicum. After ovulation, the corpus hemorrhagicum becomes the corpus luteum. Day 15-20 = the corpus luteum retains fluid over the next 4-5 days to reach a maximal size of approximately 3 cm. Day 20-28. If pregnancy doesn't occur, the corpus luteum involutes to become the corpus albicans, which cannot be seen by ultrasound. If pregnancy occurs, the corpus luteum develops into a gland secreting β-hCG. A prominent corpus luteum may be mistaken for an ectopic pregnancy due to its similar appearance. However, an ectopic pregnancy will only very rarely be in the ovary.

Renal cortical nephrocalcinosis

Dystrophic peripheral calcification of the renal cortex with sparing of the medullary pyramids usually due to diffuse cortical injury Aetiology: - Acute cortical necrosis - Chronic glomerulonephritis - Chronic transplant rejection - Hyperoxaluria (oxalises) - Alport syndrome (hereditary nephropathy and deafness). - Autosomal recessive polycystic kidney disease.

Benign adnexal cystic lesions

Paraovarian cyst - paraovarian cyst is a simple cyst separate from the ovary, thought to be developmental in origin. - paraovarian cysts are considered normal if <5 cm. - main differential is an ovarian cyst - ovarian cysts should be reported (and followed) if >3 cm, while paraovarian cysts do not need to be followed unless >5 cm - gentle pressure by the transducer displaces it away from the ovary Peritoneal inclusion cyst - septated fluid collection formed by adhesions, almost always related to prior surgery - the ovary is closely associated with the peritoneal inclusion cyst, either trapped within or adjacent to it - it is important not to recommend surgery for treatment of a peritoneal inclusion cyst, as it is benign, and further surgery may create additional adhesions - main differential of a peritoneal inclusion cyst is a cystadenoma, which has thick septations and tends to exert mass effect. Dilated fallopian tube - can be due to infection, inflammation, or traction from pelvic adhesions. - Hydrosalpinx is a fluid-filled fallopian tube lacking internal echoes. US = dilated, anechoic, paraovarian tubular structure with incomplete septations that represent infolding of the tubular walls - Hematosalpinx is a blood-filled fallopian tube that can be seen in the setting of a ruptured ectopic pregnancy or endometriosis. Imaging will show internal echoes within the dilated tube. - Pyosalpinx is a pus-filled fallopian tube resulting from pelvic inflammatory disease. As in hematosalpinx, imaging will show internal echoes within the dilated tube.

Waterhouse-Friderichsen syndrome

Patholophysiology: atraumatic adrenal haemorrhage in consequence of septicaemia Aetiology: usually Neisseria meningitidis Imaging: - non-traumatic adrenal haemorrhage

Adrenal myelolipoma

Pathophysiology: - benign neoplasm consisting of myeloid cells i.e. myeloid cells i.e. erythrocyte precursors and fat cells - rarely extra-adrenal and are indistinguishable from extramedulalry haematopoiesis Imaging: - macroscopic fat is diagnostic for myelolipoma - not to be confused with a rare liposarcoma which will displace rather than arise from the adrenal

Adrenal adenoma

Pathophysiology: - benign tumour of the cortex - occasionally produce aldosterone > conns syndrome Imaging: - macroscopic fat (<10HU = adenoma) - rapid washout on contrast-enhanced CT = absolute washout of >60% and relative washout of >40% - none of the above = indeterminate - MRI = can be used to characterise indeterminate lesions as it detects intra-cellular fat. Chemical shift artefact on GRE Collsion tumour: - presence of 2 tumours within an adrenal mass e.g. met + adenoma Washout = E-D / E-U

Xanthogranulomatous pyelonephritis

Pathophysiology: - chronic renal infection due to obstructing stag horn calculus > replacement of renal parenchyma with fibrofatty inflammatory tissue - diffuse or localised Aetiology: - proteus mirabilis - E. coli Presentation: - flank pain + nonspecific constitutional symptoms (fever + weight loss) Imaging: - CT = refatty replacement of the renal parenchyma, marked perinephric inflammatory stranding, and straghorn calculi - bear paw sign = configuration of the hypoattenuating fibrofatty masses arranged in a radial pattern, reminiscent of a bear's paw. Complications: - perinephric abscess - fistula formation - treatment = nephrectomy

Varicocele

Pathophysiology: - dilated pampiniform plexus in the scrotum - more common on the left (85%) because the left testicular vein drains into the left renal vein at a straight angle, whereas the right testicular vein drains directly into the IVC Aetiology: - primary = incompetent valves of the internal spermatic vein - secondary = increased venous pressure due to obstruction, usually a retroperitoneal mass Imaging: - >2-3 mm in diameter - usually seen in the region of the upper pole / epididymal head - valsalver

Endometrioma

Pathophysiology: - ectopic endometrial tissue implanted on the adnexa. - as endometrial tissue is hormonally responsive, an endometrioma may be composed of blood products of varying ages (chocolate cyst) - bilateral is common (30-50%) and increases specificity for the diagnosis of endometriosis Complications: - can rupture as a result of rapid growth, particularly during pregnancy > acute pelvic pain and hemoperitoneum - can lead to adhesions, tethering of bowel loops, and obliteration of the fat planes - rarely malignant degeneration into endometrioid or less commonly clear cell subtypes of ovarian cancer Imaging: US = an endometrioma may represent as a well-defined complex cyst with homogeneous low-level internal echoes and posterior acoustic enhancement - occasionally an endometrioma may appear similar to a neoplasm - MRI = typically shows multiple T1 hyperintense masses (due to hemorrhagic content) which demonstrate signal gradient ("shading") on T2-weighted images. - endometriomas ‒ unlike dermoids ‒ do not suppress on fat-saturated sequences - less commonly, endometriosis may appear hyperintense on both T1- and T2-weighted images - tiny hemorrhagic endometrial implants may be apparent as hyperintense foci on T1-weighted images note: laparoscopy is the gold standard for the diagnosis of suspected endometriosis, with implants appearing as small areas of tissue distortion with hemorrhagic spots or large masses with associated adhesions

Endometriosis / adenomyosis

Pathophysiology: - ectopic endometrial tissue outside of the endometrial cavity - three main forms: superficial masses/implants, ovarian endometriomas, and deep infiltration endometriosis Imaging: - most common sites of endometriosis include the ovaries, followed by the myometrium (adenomyosis), ligaments and peritoneal surfaces of the anterior, posterior, and middle pelvic compartments. Less common sites of endometriosis include surgical scars (post Caesarean section, myomectomy), or even rarely within organs outside of the pelvis, such as the liver surface, lungs and brain - superficial lesions: non-invasive implants, which are typically small and not visible on MRI - ovarian endometrioma: typically seen as T2 hypointense, T1 hyperintense lesions on MRI - deep (or solid) infiltrating type: defined by invasion of endometrial glands and stroma at least 5 mm beyond the peritoneal surface Adenomyosis: - ectopic endometrial tissue within the myometrium (endometriosis interna). - in contrast to endometriosis, the ectopic endometrial tissue seen in adenomyosis is nonfunctioning, and it does not respond to cyclic ovarian hormones - most patients are asymptomatic - classic clinical presentation includes dysmenorrhea, menorrhagia, dyspareunia, infertility, and chronic pelvic pain. Adenomyosis Imaging: - enlarged uterus with heterogeneous myometrium, without focal mass - multiple subendometrial cysts or echogenic foci can be found - loss of differentiation of the endometrial-myometrial junction - best seen on T2-weighted images as diffuse (or focal) thickening of the junctional zone (>12 mm), often associated with multiple small T2 hyperintense foci. Borderline thickening of the junctional zone (8-12 mm) may be due to adenomyosis, but not diagnostic. - focal adenomyosis may mimic leiomyoma, appearing as more focal T1 and T2 hypointense signal. Although imaging features may overlap, leiomyomas typically show well-defined margins, no relationship to the junctional zone, mass effect (lobular external uterine contour), and more homogeneous T2 hypointense signal.

Segmental testicular infarction

Trivia: - presents similar to torsion or epididymitis - focal infarction - typically in their thirties - Aetiology: - microvascular thrombosis from acute inflammation, vasculitis, or sickle cell disease Imaging: - wedge shaped area of hypo echoic teste - may undergo necrosis Ddx is hypo vascular tumour > MRI to help if concern for that

Congenital uterine malformations

Trivia: - caused by abnormal development of the paired Müllerian ducts, which normally fuse during embryogenesis. A septate uterus is the most common congenital abnormality, followed by bicornuate uterus - increase risk of infertility or recurrent pregnancy loss because the uterine cavity is abnormal in size (often small, multiple) or morphology - congenital uterine abnormalities are associated with urinary tract abnormalities such as renal ectopia or agenesis Arcuate: - small indentation of the fundal surface of the endometrial cavity, with indentation depth <10 mm and angle >90 degrees. - usually incidental and asymptomatic, and rarely associated with pregnancy loss - often considered a normal variant rather than an anomaly Septate: - two uterine cavities, divided by a fibrous or muscular septum (>15 mm indentation depth, angle <90 degrees). External fundal contour is convex. - most likely of all uterine anomalies to be implicated in pregnancy loss since the fibrous septal tissue or myometrium is relatively avascular - metroplasty (resection of the septum) can be performed hysteroscopically if the septum is fibrous, or transabdominally if the septum is muscular Bicornate: - two uterine fundi with shared lower uterine segment; can have one cervix (bicornis unicollis) or two cervices (bicornis bicollis). - concave external fundal contour which pinches inwards > 15 mm Didelphys: - two completely separate uteri and cervices, with complete endometrium, myometrium and serosal surfaces on each side - 75% have a vaginal septum DES uterus: - in utero exposure to diethylstilbestrol (DES) causes the fetus to develop classic imaging appearanceof hypoplastic uterus with a T-shaped endometrial contour. - associated with an increased risk of clear cell vaginal cancer - DES has not been used since the 1970s

Renal medullary carcinoma

Trivia: - infiltrative, extremely aggressive neoplasm - mean survival of 15 months, not helped by chemotherapy - mostly affects young adult males with sickle cell trait Imaging: - CT = ill-defined, infiltrative, hypovascular central renal mass - necrosis and hemorrhage are common - similar to renal transitional cell carcinoma, which occurs in an older population

Non-seminomatous germ cell tumors (NSGCT)

Trivia: - men in 20-30s - more aggressive than seminoma - local invasion into tunica albuginea and visceral mets are common Imaging: - herogenous testicular mass with cystic and solid components + coarse calcifications Subtypes: - mixed germ cell - embryonal cell carcinoma - teratoma - choriocarcinoma

Endometrial carcinoma

Trivia: - most common female gynecologic malignancy - caused by prolonged estrogen exposure - risk factors = nulliparity, hormone replacement therapy (HRT), and tamoxifen - >95% of endometrial carcinoma presents with postmenopausal bleeding Imaging: - the average endometrial thickness of patients with endometrial carcinoma is 21 mm - endometrial thickness ≥5 mm requires further workup (usually biopsy and/or hysteroscopy) or 8 mm on HRT - ill-defined margins separating the endometrium and the myometrium Staging: - MRI - depth of myometrial invasion

Retroperitoneal liposarcoma

Trivia: - most common primary retroperitoneal malignancy 5 histological subgroups: - well-differentiated type (mostly fat) is most common and least aggressive - myxoid - round-cell - pleomorphic - dedifferentiated more aggressive subtypes have less fat and become indistinguishable from other soft tissue masses

Testicular seminoma (type of germ cell tumour)

Trivia: - most common testicular malignancy - favourable prognosis - middle aged men - accounts for half of all GCTs - uncommonly, hCG may be elevated. Imaging: - hypo-echoic - typically more homogenous than other testicular tumours - hyper-vascular

Fournier gangrene

Trivia: - necrotizing fasciitis of the scrotum and perineum, a highly morbid and surgically emergent condition - infection is usually polymicrobial Imaging: - presence of subcutaneous gas, often evaluated with CT

Burnt-out GCT

Trivia: - no longer viable in teste though often viable metastatic disease (especially retroperitoneal disease) Imaging: - focal calcification in the teste Treatment: - orchiectomy + chemo

tubular ectasia of the rete testis

Trivia: - nonpalpable, asymptomatic, cystic dilation of the tubules at the mediastinum testes caused by epididymal obstruction - common in older patients and may be bilateral - benign and no treatment is necessary. Imaging: - numerous tiny dilated structures in the region of the mediastinum testis, often seen in conjunction with an epididymal cyst/spermatocele

Ovarian cancer

Trivia: - ovarian cancer is the tenth most common female malignancy, but ranks fifth in cancer deaths among women as it often presents at a late stage Types: - ovarian cancer may be epithelial, germ cell, sex cord-stromal, or metastatic in origin. - 90% of malignant tumors are of epithelial - serous tumors are the most common epithelial subtype, followed by mucinous, endometrioid, and clear cell -serous cystadenocarcinomas are frequently bilateral and typically appear as mixed solid and cystic masses. The solid portions demonstrate avid enhancement. There is often concomitant ascites. - mucinous cystadenocarcinomas are large, most commonly unilateral, and occur in older patients compared to serous cystadenocarcinomas. Mucinous cystadenocarcinoma typically presents as a multiloculated cystic mass containing mucin-rich T1 hyperintense fluid. - clear cell carcinoma and less commonly endometrioid carcinoma are associated with endometriosis. - malignant germ cell tumors occur in younger patients and include dysgerminoma, endodermal sinus tumor, and immature teratoma. Metastases: - uncommon but may result from gastric cancer, colon cancer, pancreatic cancer, breast cancer, and melanoma - often bilateral. - krukenberg tumor is an ovarian metastasis of a mucin-producing tumor, typically gastric or colonic adenocarcinoma. Endometrial cancer may also metastasize to the ovaries Imaging: - US = Mural nodule, thick or irregular walls or septae, solid components, high flow on color Doppler, presence of ascites, papillary projections - MRI is used to characterize indeterminate adnexal masses, rather than for staging = arge size (>10 cm), solid enhancing component(s), internal necrosis, ascites, or peritoneal nodularity Staging:

Endometrial polyp

Trivia: - presentation = mucous discharge or irregular vaginal bleeding between cycles - mostly benign, but larger polyps (>1.5 cm) occurring in postmenopausal patients may have malignant potential Imaging: - focal nodular area of endometrial thickening, often with a feeding vessel or internal flow by Doppler

Testicular haematoma

peripheral hypoechoic lesion that may mimic tumor. Even with a history of trauma, a suspicious testicular lesion requires further evaluation to exclude malignancy, typically with a short-term follow-up.

Renal Cell Carcinoma

Trivia: - most common solid renal mass - arises from renal tubular epithelium - 2-3% of all cancers. - RCC has a propensity for venous invasion, which significantly alters surgical approach. Risk factors: - smoking - acquired cystic kidney disease - von Hippel-Lindau (VHL) - tuberous sclerosis. Staging of RCC is based on the Robson system, which characterizes fascial extension and vascular/lymph node involvement. Stages I-III are usually resectable, although the surgical approach may need to be altered for venous invasion (stages IIIA and IIIC). Imaging: - US = usually isoechoic to renal cortex, but can be hypo- or hyperechoic - If hyperechoic (mimicking AML), imaging features such as a hypoechoic rim and intratumoral cystic changes favor RCC. - Color and spectral Doppler are helpful in differentiating bland renal vein thrombus (which would not be stage IIIA) from tumor thrombus. Tumor thrombus will have color Doppler flow with an arterial waveform. Subtypes: Clear cell RCC is the most common subtype (~75%), with 5-year survival of ~55%.Clear cell RCC tends to enhance more avidly than the less common subtypes. Clear cell can be sporadic or associated with Von Hippel-Lindau. MRI shows T2 hyperintense signal with marked enhancement. Papillary RCC is a hypovascular subtype, with a 5-year survival of 80-90%. Papillary RCC tends to enhance only mildly due to its hypovascularity. A renal "adenoma" is frequently seen on autopsy specimens and is a papillary carcinoma ≤5 mm. MRI shows T2 hypointensity with mild enhancement. Chromophobe is the subtype with the best prognosis, featuring a 90% 5-year survival. Sarcomatoid differentiation can occur with subtypes above, resembling sarcoma with an aggressive behavior and poor prognosis. The enhancement kinetics can help differentiate the subtypes of RCC.

Uterine leiomyosarcoma

Trivia: - rare and may arise de-novo or from malignant degeneration of a fibroid - tamoxifen increases the risk of leiomyosarcoma in addition to endometrial carcinoma Imaging: - a "funny looking fibroid" is much more likely to be a benign inhomogeneous fibroid rather than a leiomyosarcoma, but rapid growth should raise suspicion. - although signal heterogeneity, restricted diffusion, internal hemorrhage, and ill-defined contour have been described in leiomyosarcomas, imaging cannot reliably differentiate between leiomyoma and leiomyosarcoma. - in the absence of obvious malignant features (such as local invasion or regional metastases), an unusual-looking fibroid is overwhelmingly likely to represent a degenerating benign fibroid rather than a leiomyosarcoma.

Extra-calyceal contrast material

Tubular ectasia (causes paint-brush like streaks of contrast that extend from the papillae into the tubules on excretory urogram Medullary sponge kidney (tubular ectasia + associated calcifications) Papillary necrosis (outpouching of the collecting system into the corticomedullary region)

Urethral stricture

Urethral strictures secondary to sexually transmitted disease (most commonly chronic urethritis from Neisseria gonorrhoeae) occur most commonly in the bulbous urethra. A complication of chronic urethral infection is a periurethral abscess, which may result in a urethroperineal fistula. Post-traumatic saddle injury strictures also tend to occur in the bulbous urethra. Iatrogenic stricture from a Foley catheter tends to occur in the penile urethra

Extra-testicular masses

Usually benign (16% malignant) spermatic cord lipoma is most common adenomatoid tumour of the tunica albuginea is most common epididymal neoplasm

Vaginal malignancy

Vaginal cancer Squamous cell carcinoma of the vagina accounts for 80-85% of primary vaginal malignancies and usually presents in older women. It is associated with HPV similar to SCC of the cervix. Adenocarcinoma of the vagina presents in younger women (15% of vaginal malignancies) and can arise from vaginal adenosis. Clear cell carcinoma of the vagina is rare and associated with previous diethylstilbestrol (DES) exposure. These patients will often have a "T-shaped" uterus, described later in the uterine malformations section. Primary vaginal melanoma is rare and most commonly presents in postmenopausal women. It has an aggressive course. Vaginal sarcoma presents as rhabomyosarcoma in the pediatric population. This is the most common vaginal tumor in children. It has a bimodal distribution, usually ages 2-6 and 14-18. Vulvar cancer • Vulvar cancer commonly involves the labia majora and minora, accounting for up to 5% of female genital tract malignancies with peak age 65-70 years old. Metastasis Metastasis to the vagina can occur from the upper genital tract or the GI tract. Metastasis located in the upper 1/3 of the vagina (typically anterior) is usually from the upper genital tract. Metastasis located in the lower 1/3 (typically posterior) is usually from the GI tract.

Amgiomyolipoma

benign hamartoma made up of - blood vessels - muscle - fat Trivia: - most common benign renal neoplasm - most occur sporadically but unilateral and solitary), but 40% are associated with tuberous sclerosis (typically multiple and bilateral) - >4 cm in size = risk of hemorrhage due to microaneurysm rupture Imaging: - presence of macroscopic fat in a non-calcified renal lesion is diagnostic of AML. - nonfat-containing portion enhances avidly and homogeneously - calcification is rare in AMLs and should raise suspicion for RCC with macroscopic fat. - US = echogenic due to the fat component. There is considerable overlap between the ultrasound appearance of AML and RCC. About one-third of AML demonstrate shadowing, which is a specific finding for AML. - MRI = fat component will follow retroperitoneal fat on all sequences and will saturate out on fat-saturated sequences. The muscle component will be T2 hypointense. Intracytoplasmic lipid is not a feature of AML, so there should be no significant signal drop- out on dual-echo in- and out-of-phase images on MRI. - 4% of AMLs lack macroscopic fat and appear as hyperdense enhancing mass on CT. In such cases, MRI can be helpful. A T2 hyperintense mass is suggestive of clear cell RCC or less likely oncocytoma. A T2 hypointense mass may represent a fat-poor AML or papillary RCC, thus biopsy is usually recommended for definitive diagnosis. In rare cases, RCC with macroscopic fat has been described.

Renal medullary nephrocalcinosis

calcification of the medullary pyramids Aetiology: - any aetiology that leads to hypercalcaemia or hypercalciuria e.g: - hyperparathyroidism (most common) - medullary sponge kidney - sarcoidosis (hypercalcaemia) - T1 renal tubular acidosis (RTA) - papillary necrosis - furosemide in children

Fibroid

common benign tumors of smooth muscle seen in reproductive-age women. A lipoleiomyoma is a variant of fibroid which contains fat and is echogenic on US. Fibroids can be found in several locations: - Intramural: located within the myometrium; most common location. - Submucosal: directly underneath the endometrial mucosa and may bulge into the endometrial canal. A submucosal fibroid can be resected hysteroscopically if >50% of the fibroid is intraluminal. An intracavitary fibroid is a variant which is located nearly entirely within the endometrial cavity. - Subserosal: directly underneath the outer uterine serosa. A subserosal fibroid may simulate an adnexal mass if pedunculated, but Doppler will show blood supply coming from the uterus. - Cervical: rare, may simulate cervical cancer. The typical ultrasound appearance of a fibroid is a slightly heterogeneous, hypoechoic uterine mass with linear bands of shadowing. Calcification is often seen.May undergo cystic degeneration and appear as an anechoic mass with posterior through-transmission. MRI: - T2 hypointense due to the presence of compact smooth muscle but up to 2/3 of leiomyomas show some form of degeneration. - internal cystic or myxoid degeneration may increase T2 signal heterogeneously. - red (carneous) degeneration due to hemorrhagic infarction, often during pregnancy or following oral contraceptive pill (OCP) use, may appear T1 hyperintense. Calcifications are common and can be seen in up to 25% of cases. MRI is often performed for treatment planning prior to uterine artery embolization(UAE). Hemorrhagic or necrotic leiomyomas are not treated effectively by UAE. Surgical myomectomy or hysterectomy would be the preferred treatment in these cases. Additionally, there is less chance of UAE success if an ovarian-uterine artery anastomosis is present.

Unilateral kindey enlargement

compensatory hypertrophy Pyelonephritis Acute obstruction Renal vein thrombosis

Scrotal haematoma

echogenic, extra-testicular mass with no Doppler flow. When large, the hematoma can compress the testicle.

Epididymal cyst / spermatocele / testicular cyst / tunic cyst

epididymal cysts and spermatocele cannot be reliably differentiated on US (both can occur anywhere in the epididymus) testicular cyst in teste tunic cyst = cyst of the tunica albuginea. Presents as a palpable superficial nodule that resembles a BB. US shows small extra-testicular cyst

Diffusely increased echogenicity kidney US

medical renal disease e.g: - DM nephropathy - glomerulosclerosis - acute tubular necrosis - HIV nephropathy (will be enlarged)

Ureteral transitional Cell Carcinoma / Urothelial cell carcinoma

most common ureteral cancer Imaging: - typically = single short segment of wall thickening, stricture, or filling defect at the excretory phase. - However, multiple filling defects may be seen in 40%. - Given the propensity of TCC for multifocal disease, the bladder should be evaluated for a synchronous mass.

Testicular microlithiasis

multiple punctate intratesticular calcifications Imaging: - at least 5 microcalcifications must be present per image to be called microlithiasis - less than 5 microcalcifications the term limited microlithiasis is used. - starry sky appearance if calcifications are numerous.In the liver (hepatitis can cause a starry sky appearance due to increased echogenicity of the portal triads) note: There is a controversial association between microlithiasis and testicular neoplasm. While the overall absolute risk for developing testicular cancer remains very small in the presence of microlithiasis, the relative risk may be increased. Current guidelines do not support screening by ultrasound or tumor markers, but patients with microlithiasis may perform self-examinations and be seen in follow-up as needed.

Adrenal calcification

not infrequent rarely causes hypo-function Aetiology: - haemorrhage - granulomatosis with polyangitis - TB - histoplasmosis