Pathology Exam 2 Study Questions + Extras

One week after a mild flulike illness, a 9-year-old boy has an episode of hematuria that subsides within 2 days. One month later, he tells his parents that his urine is red again. On physical examination, there are no significant findings. Urinalysis shows a pH of 7; specific gravity 1.015; 1+ proteinuria; 1+ hematuria; and no ketones, glucose, or urobilinogen. The serum urea nitrogen level is 36 mg/dL, and the creatinine level is 3.2 mg/dL. A renal biopsy specimen shows diffuse mesangial proliferation and electron-dense deposits in the mesangium. Which of the following mechanisms is most likely to produce these findings? (A) Deposition of immune complexes containing IgA (B) Formation of antibodies against type IV collagen (C) Virus-mediated injury to the glomeruli (D) Cytokine-mediated injury to the glomerular capillaries (E) Congenital defects in the structure of glomerular basement membranes

(A) Development of recurrent hematuria after a viral illness in a child or young adult is typically associated with IgA nephropathy. In these patients, some defect in immune regulation causes excessive mucosal IgA synthesis in response to viral or other environmental antigens. IgA complexes are deposited in the mesangium and initiate glomerular injury. Antibodies against type IV collagen are formed in Goodpasture syndrome. Although viruses induce IgA synthesis, they do not cause direct glomerular damage. Cytokine-mediated injury can occur in transplant rejection. Defects in the structure of glomerular basement membrane are a feature of hereditary nephritis.

A 45-year-old man has had headaches, nausea, and vomiting that have worsened over the past 5 days. He has started "seeing spots" before his eyes. On physical examination, his blood pressure is 268/150 mm Hg. Urinalysis shows 1+ proteinuria; 2+ hematuria; and no glucose, ketones, or leukocytes. The serum urea nitrogen and creatinine levels are elevated. Which of the following histologic findings is most likely to be seen in this patient's kidneys? (A) Nodular glomerulosclerosis (B) Segmental tubular necrosis (C) Hyperplastic arteriolosclerosis (D) Mesangial IgA deposition (E) Glomerular crescents

(C) This patient has malignant hypertension, which may follow long-standing benign hypertension. Two types of vascular lesions are found in malignant hypertension.Fibrinoid necrosis of the arterioles may be present; in addition, there is intimal thickening in interlobular arteries and arterioles, caused by proliferation of smooth muscle cells and collagen deposition. The proliferating smooth muscle cells are concentrically arranged, and these lesions, called hyperplastic arteriolosclerosis, cause severe narrowing of the lumen. The resultant ischemia elevates the renin level, which further promotes vasoconstriction to potentiate the injury. Nodular glomerulosclerosis is a feature of diabetes mellitus that slowly progresses over many years. Segmental tubular necrosis occurs in ischemic forms of acute tubular necrosis. An IgA nephropathy involves glomeruli, but not typically the interstitium or vasculature. Glomerular crescents are a feature of a rapidly progressive glomerulonephritis; however, the blood pressure elevation is not as marked as that seen in this patient.

A 7-year-old boy is recovering from impetigo. Physical examination shows a few honey-colored crusts on his face. The crusts are removed, and a culture of the lesions grows group A Streptococcus pyogenes. He is treated with antibiotics. One week later, he develops malaise with nausea and a slight fever and passes dark brown urine. Laboratory studies show a serum antistreptolysin O titer of 1:1024. Which of the following is the most likely outcome? (A) Development of rheumatic heart disease (B) Chronic renal failure (C) Lower urinary tract infection (D) Complete recovery without treatment (E) Progression to crescentic glomerulonephritis

(D) These findings are characteristic of poststreptococcal glomerulonephritis. The strains of group A streptococci that cause poststreptococcal glomerulonephritis differ from the strains that cause rheumatic fever. Most children with poststreptococcal glomerulonephritis recover, although perhaps 1% develop a rapidly progressive glomerulonephritis. Progression to chronic renal failure occurs more frequently in affected adults. A urinary tract infection is not likely to accompany poststreptococcal glomerulonephritis because the organisms that caused the immunological reaction are no longer present when symptoms of glomerulonephritis appear.

A 25-year-old woman experiences sudden onset of fever, malaise, and nausea. On physical examination, her temperature is 38.2°C, pulse is 85/min, respirations are 18/min, and blood pressure is 140/90 mm Hg. A routine urinalysis shows 1+ proteinuria, 4+ hematuria, and no ketones or glucose. RBC casts are seen on microscopic examination of the urine. A renal biopsy is performed, and light microscopic examination shows marked glomerular hypercellularity with neutrophils in glomerular capillary loops. Immunofluorescence microscopy shows granular deposition of IgG and C3 in glomerular capillary basement membranes. Electron microscopy shows electron-dense subepithelial "humps." What is the most likely diagnosis? (A) Goodpasture syndrome (B) Systemic amyloidosis (C) Membranous glomerulonephritis (D) Diabetes mellitus (E) Postinfectious glomerulonephritis

(E) Postinfectious glomerulonephritis is one of many causes of a nephritic syndrome characterized by hematuria and RBC casts. Most children recover completely, but one in six adults may progress to chronic renal failure. Some cases may occur after a streptococcal pharyngitis (poststreptococcal glomerulonephritis). In other cases, such as this one, the preceding infection is so mild that patients give no history. Goodpasture syndrome also may produce a nephritic syndrome, but there is linear deposition of antibody in the glomerular basement membrane. Amyloidosis of the kidney mainly produces proteinuria without hematuria, as does membranous glomerulonephritis. Nodular and diffuse glomerulosclerosis are characteristic of diabetic nephropathy.

A 28 years old woman has had malaise, arthralgias, and myalgias for the past 3 months. There is no joint swelling or deformity. Lab studies show a serum creatinine level of 3.9 mg/dL. A renal biopsy specimen shows a proliferative glomerulonephritis. She receives corticosteroid therapy for 4 months. Now, she comes back and complains of left hip pain with movement. On physical examination, there is no swelling or deformity. An X-ray of the left leg shows lower density of the femoral head with flattening of the bone. A total replacement of the left hip is performed, and gross examination of the sectioned femoral head shows collapse of articular cartilage over a pale, wedge-shaped, subchondral area. What is the most likely diagnosis? A) Avascular necrosis B) Osteomyelitis C) Osteoarthritis D) Enchondroma

A) Avascular necrosis

A 25-year-old obese woman who denies any history of alcohol abuse presents with severe abdominal pain radiating to the back. Laboratory results indicate an increase in serum amylase and lipase, with a marked decrease in calcium. Her US is shown. Which of the following likely has caused this condition? A) Cholelithiasis B) Abetalipoproteinemia C) Cystic fibrosis D) Alcohol

A) Cholelithiasis

A 8 years old girl presents with a tibial mass, the pathology examination reveals a tumor of small round blue cells with formation of rosette pattern. Which of the following molecular findings is most likely to be present? A) Chromosome 22 translocation B) Chromosome 11 deletion C) Chromosome 1 deletion D) Chromosome 7 translocation

A) Chromosome 22 translocation

A 10-day-old infant presents with projectile vomiting. His mother states that the infant will actively drink his milk, but he forcefully vomits after each feeding. The infant shows signs of failure to thrive, with weight loss, dehydration, and lethargy. Physical examination reveals a firm, non-tender, mobile, "olive-shaped" epigastric mass. The imaging study is shown. Which of the following is the most likely diagnosis? A) Congenital pyloric stenosis B) GERD C) Candida esophagitis D) Esophageal cancer

A) Congenital pyloric stenosis

A 33 years old woman complains of painless, nodular lesions on two fingers of her right hand. A radiograph reveals bulbous radiolucent swellings. A biopsy shows well differentiated proliferation of hyaline cartilage. Which of the following is the most probably diagnosis? A) Enchondroma B) Chondrosarcoma C) Synovial sarcoma D) Osteosarcoma

A) Enchondroma

A 21-year-old black woman presents with fever, malaise, generalized arthralgias, and a skin rash over the nose and malar eminences. Which one of the following possible findings has the greatest relative significance in the overall prognosis for the patient? A) Glomerular subendothelial immune complex deposition B) Pleuritis C) Atypical verrucous vegetations of the mitral valve D) Perivascular fibrosis in the spleen

A) Glomerular subendothelial immune complex deposition

A 56-year-old male is diagnosed with pancreatic adenocarcinoma. He undergoes a Whipple procedure and has a 20-year postoperative survival, with no recurrence of the tumor. Of the following, what was the most likely site of the tumor? A) Head of the pancreas B) Tail of the pancreas C) Proximal body of the pancreas D) Distal body of the pancreas

A) Head of the pancreas

A 70-year-old man presents with fatigue, weight loss, abdominal pain, and overt blood in the stools. A complete blood count reveals anemia with hemoglobin of 10.0 g/dL. A colonoscopy and colon biopsy reveal adenocarcinoma. Which of the following is not a predisposing lesion that lead to this condition? A) Hyperplastic polyp B) Villous adenoma C) Tubular adenoma D) Long-standing ulcerative colitis

A) Hyperplastic polyp

A 32-year-old woman seeking to become pregnant visits her health clinic for a pre-pregnancy examination. Routine prenatal laboratory testing demonstrates the following profile: HBsAg (−), anti-HBsAg (+), anti-HBcAg (−), anti-HBeAg (−), and HBV DNA (−). Which of the following likely represents the status of the patient? A) Immunized against hepatitis B B) Infected and within the "window period" C) Hepatitis B carrier D) Infected with hepatitis B and highly transmissible

A) Immunized against hepatitis B

A 60-year-old white man with a 5-year history of gastroesophageal reflux disease (GERD) presents with persistent heartburn and acid regurgitation. He has had similar symptoms for the past 5 years. Because this patient has a long history of GERD, an endoscopy is performed to screen for Barrett esophagus. Results reveal that Barrett esophagus is indeed present. Which of the following is true of Barrett esophagus? A) It is a known precursor of adenocarcinoma of the esophagus. B) It is a known precursor of carcinoma of the stomach. C) A biopsy will show a histologic finding of columnar-to-squamous metaplasia. D) It is a known precursor of squamous cell carcinoma of the esophagus.

A) It is a known precursor of adenocarcinoma of the esophagus.

A 56 years old man presents with a lump in the soft tissue of his back. Physical examination reveals a 0.6 cm subcutaneous tumor. Biopsy (bx) of the mass shows a benign neoplasm. The patient is told that he has the most common soft tissue tumor. What is the diagnosis? A) Lipoma B) Pleomorphic adenoma C) Fibroma D) Leiomyoma

A) Lipoma

A 51 years old man has had dull, constant pain in the midsection of the right thigh for the past 5 months. There is pain on palpation of the anterior right thigh, which worsens with movement. The right thigh appears to have a larger circumference than the left thigh. An X-ray of the right upper leg and pelvis shows no fracture, but there is an ill-defined soft-tissue mass anterior to the femur. MRI shows a 11 × 7 × 8 cm solid mass deep to the quadriceps, but it does not involve the femur. Cytogenetic studies of tumor cells reveals t(12;16) with amplification of MDM2 gene. What is the most likely diagnosis? A) Liposarcoma B) Chondrosarcoma C) Metastatic adenocarcinoma D) Nodular fasciitis

A) Liposarcoma

A 28 years old man is hit on the right arm by a steel beam while working. On examination, a 5 cm area of the lateral upper right arm shows swelling and redness with pain on palpation. An X-ray shows no fracture. 4 weeks later, there is now a 2 cm painful, well circumscribed, subcutaneous mass at the site of the original injury. An X-ray shows a solid soft-tissue mass. Which of the following lesions is most likely to be present in this man? A) Nodular fasciitis B) Lipoma C) Organizing abscess D) Superficial fibromatosis

A) Nodular fasciitis

A 13-year-old boy has had sudden onset of severe pain in his left knee that has awakened him from sleep during the past 8 weeks. His mother has given him acetylsalicylic acid (aspirin), and the pain has been relieved. On physical examination, there are no remarkable findings. An MRI of the left knee shows a well-defined, 0.9 cm lucent area surrounded by a thin rim of bony sclerosis located in the proximal tibial cortex. He undergoes radio ablation of the lesion, and the pain does not recur. What is the most likely diagnosis of this lesion? A) Osteoid osteoma B) Enchondroma C) Fibrous dysplasia D) Giant Cell Tumor

A) Osteoid osteoma

A 7 yo girl has had pain around the left hip for the past 3 weeks. On PE, her temp is 38.2 deg C. There is swelling w/ tenderness to palpation around the hip, pain, and reduced range of motion. X-rays of the pelvis and legs show areas of osteolysis and cortical erosion involving the femoral metaphysis, w/ adjacent soft tissue swelling extending from the sub periosteal region, and probable abscess formation. Which of the following organisms is most likely to produce these findings? A) Staph aureus B) Group B Strep C) H. influenzae D) N. gonorrhoeae

A) Staph aureus

A 43-year-old male has, over the past year, presented to his family health clinic with complaints of intermittent diarrhea, which is occasionally bloody, and abdominal pain, and received a variety of diagnoses, from acute gastritis to presumed diverticulosis. During this time, he has lost 15 lbs. He is referred to a gastroenterologist who performs a barium enema and identifies narrowed regions of the large intestine intermingled with normal regions. Given this clinical scenario, of the following, which condition is this patient most likely to develop? A) Uveitis B) Primary biliary cirrhosis C) Glaucoma D) Primary sclerosing cholangitis

A) Uveitis

A 70-year-old man is sent for liver biopsy by his P.A. after a workup for jaundice revealed a liver mass. The Bx shows angiosarcoma. Exposure to which of the following agents is a risk factor for this malignancy? A) Vinyl chloride B) Aflatoxin C) Aldehydes D) Naphthalene

A) Vinyl chloride

You are shown a colectomy specimen. The colonic mucosa has a 3.0-cm invasive neoplasm, and in the surrounding mucosa are an estimated 450 polyps. Of the following, the mutation of which gene produced these findings? A) KIT B) APC C) DNA mismatch repiar gene D) MYC

B) APC

A 43-year-old multigravida presents with nausea, vomiting, fever, and right upper quadrant pain. On examination, she displays arrested inspiration on palpation of the right upper quadrant (Murphy sign). Her laboratory results reveal neutrophilia with a "left shift." Which of the following is the most likely diagnosis? A) Cholesterolosis B) Acute cholecystitis C) Cholangiocarcinoma D) Sclerosing cholangitis

B) Acute cholecystitis

A 43-year-old alcoholic presents to the emergency room with complaints of abdominal pain, which developed suddenly about one day ago and is in the epigastric region but also affects his back. Admission laboratory testing reveals a white blood cell count of 18,000/µL, hemoglobin of 14 g/dL, hematocrit of 38, ALT of 98 U/L, AST of 88 U/L, GGT of 121 U/L, alkaline phosphatase of 870 U/L, amylase of 332 U/L, and lipase of 650 U/L. Of the following, what is the most likely diagnosis? A) Alcoholic hepatitis B) Acute pancreatitis C) Acute myocardial infarct D) Acute cholecystitis

B) Acute pancreatitis

A 36-year-old man from sub-Saharan Africa presents to the clinic with jaundice and right upper quadrant pain. On examination, the liver is palpably enlarged. Lab studies demonstrate an increase in liver enzymes. Computed tomography demonstrates a single large mass in the right lobe of the liver, and serum α-fetoprotein is markedly elevated. Which of the following is likely to have contributed to the patient's condition? A) C. sinensis B) Aflatoxin C) Hepatitis A D) Polyvinyl chloride

B) Aflatoxin

A 41-year-old woman presents to the emergency room. She has had two days of abdominal pain and diarrhea, and, starting today, she has seen blood in the diarrhea, which prompted her visit to the emergency room. Associated with the diarrhea she has felt malaise and fatigue. Her past medical history includes systemic lupus erythematous. Also, she was diagnosed with a urinary tract infection two weeks ago and placed on ciprofloxacin by her primary care provider. Her vital signs are a temperature of 99.7F, pulse of 108 bpm, and blood pressure of 116/72 mmHg. A colonoscopy image is shown. Of the following, what is the most likely cause of her diarrhea? A) Inflammatory bowel disease B) Clostridium difficile C) Crohn's disease D) Salmonella

B) Clostridium difficile

What are the expected findings on electron microscopic examination of the glomerulus from a patient with diagnosis of acute post-infectious glomerulonephritis? A) No changes except for fused epithelial foot processes B) Electron-dense "humps" in sub-epithelial location C) Marked thickening of the GBM with numerous intramembranous and sub-epithelial immune complex deposits D) Marked subendothelial immune complex deposition

B) Electron-dense "humps" in sub-epithelial location -> when you see "humps" or "lumpy bumpy" think post-infectious GN

A 25-year-old African American man presents with generalized edema. Blood tests reveal severe proteinuria, hypoalbuminemia, and hyperlipidemia. The patient does not respond well to a course of corticosteroids. A renal biopsy demonstrates collagen scarring, as shown in the figure, affecting less than 50% of glomeruli. Which of the following is the most likely diagnosis? A) Lupus nephropathy B) Focal segmental glomerulosclerosis C) Diabetic nephropathy D) Membranous glomerulonephritis

B) Focal segmental glomerulosclerosis -> key is <50%

A 20-year-old white woman with the nephrotic syndrome and slowly progressive impairment of renal function marked by azotemia (abnormal increased levels of BUN and creatinine) undergoes a renal biopsy. The patient's response to corticosteroid medication has been unimpressive. The PAS stain and immunofluorescence biopsy shown in the figure. The most likely diagnosis is A) Poststreptococcal glomerulonephritis B) Membranous glomerulonephritis C) Minimal change disease D) Focal segmental glomerulosclerosis

B) Membranous glomerulonephritis PSG: after strep, usually kids MCD: in kids FSGS: usually African American or Hispanic pts

A 63-year-old female presents to the emergency room with a two-day history of abdominal pain, which started suddenly and has gotten worse over the past two days. She was brought in by her sister, as she was too sick to drive, and because her sister was concerned for her health, not thinking she had a stomach flu. Despite treatment, she dies. At autopsy, her small and large intestine, from the proximal jejunum to the midportion of the transverse colon, is observed to be dark red and discolored. In addition she has 1,400 mL of cloudy yellow fluid in her peritoneal cavity and fibrinous adhesions between loops of intestine. Of the following, what is the most likely diagnosis? A) Giant cell arteritis involving the superior mesenteric artery B) Thrombosis of an atherosclerotic plaque of the superior mesenteric artery C) Sponataneous dissection of the superior mesenteric artery D) Dysplasia of the superior mesenteric artery

B) Thrombosis of an atherosclerotic plaque of the superior mesenteric artery

A 66-year-old male presents to his family health clinic with complaints of fatigue. After determining that the fatigue is not psychogenic in origin, his health provider conducts a physical examination and notes some slight pain with pressure in the right lower quadrant of the abdomen and a positive fecal occult blood test. Laboratory testing reveals a hemoglobin of 10.4 mg/dL. A barium enema does not reveal any abnormalities but illustrates only the transverse and descending segments of the large intestine. The patient has no history of changes in bowel habits. Of the following, what is the most likely diagnosis? A) Acute appendicitis B) Celiac disease C) Colonic adenocarcinoma D) Diverticulosis

C) Colonic adenocarcinoma

A 26-year-old woman presents to her primary care provider with fever, malaise, and "yellow eyes." She denies alcohol abuse but admits to indulging in a dozen raw oysters at happy hour 3 weeks ago. In addition to scleral icterus, physical examination reveals a mildly enlarged liver with tenderness to palpation. Laboratory studies demonstrate a markedly increased aspartate aminotransferase and alanine aminotransferase and increased IgM and anti-hepatitis A titers. Which of the following is the most likely result of this infection? A) Establishment of a chronic carrier state B) Fulminant hepatitis C) Complete resolution D) Cirrhosis

C) Complete resolution

A 32-year-old male has had multiple presentations to his family health clinic and an acute care clinic with complaint of intermittent diarrhea, which occasionally contains blood. He has also lost 20 lbs over the past several months. Associated with these symptoms, he frequently has abdominal pain. A barium study identifies erosions and strictures in the last portion of the small intestine. Of the following, what is the most likely diagnosis? A) Pseudomembranous colitis B) Ulcerative colitis C) Crohn's disease D) Diverticulitis

C) Crohn's disease

A 12 years old boy has had pain in the right leg for the past 4 weeks. There is no history of trauma or recent illness. There is warmth and tenderness to palpation of the right lower thigh anteriorly, and the circumference of the right thigh is slightly larger than that of the left. His temperature is 39° C. A radiograph of the right leg shows a 58 cm mass in the diaphyseal region of the right lower femur that extends into the soft tissue and is covered by layers of reactive bone. A biopsy shows sheets of packed primitive cells with small, uniform nuclei and only scant cytoplasm. Karyotypic analysis of the tumor cells shows a t(11;22) translocation. What is the most likely diagnosis? A) Osteosarcoma B) Chondrosarcoma C) Ewing sarcoma D) Metastatic carcinoma

C) Ewing sarcoma

A 67-year-old male who lives in Montana and does not travel outside the state is brought to the ER by his family because he has become disoriented in the past few days, not knowing who he was or where he was at. They say that over the past several months, he has had some difficulty in remembering events from the daym including what he had for meals, which was a behavior that they just ascribed to old age. Also, for about the past year, he has complained to them of intermittent diarrhea and joint pain. Prior to the past year, he has been relatively healthy, only diagnosed with hypertension, which has been well controlled with medication. An intestinal biopsy reveals a PAS positive stain. Of the following, which is the most likely cause of his symptoms? A) Streptococcus pneumoniae B) E. coli C) Tropheryma whipplei D) Borrelia burgdorferi

C) Tropheryma whipplei

Which of the following histopathologic finding is seen in schwannoma? A) Storiform pattern B) Small round cells C) Target Cells D) Antoni A Pattern

D) Antoni A Pattern

A 55-year-old alcoholic man died after an illness characterized by increasing jaundice, ascites, and generalized wasting. Lab testing revealed hyperbilirubinemia, hypoalbuminemia, and mildly elevated liver enzymes. The appearance of the liver at autopsy is shown in the figure. The most likely diagnosis is: A) Hepatitis C. B) Alpha 1-antitrypsin deficiency. C) Hepatitis A. D) Cirrhosis.

D) Cirrhosis.

While on an international medical rotation, you encounter a pregnant woman in a rural village in India who presents with fever, jaundice, and malaise. The patient unexpectedly expires. This is the second case this month with a similar presentation. Which of the following is the most likely form of hepatitis? A) Hepatitis C B) Hepatitis A C) Hepatitis B D) Hepatitis E

D) Hepatitis E

A newborn male who failed to pass meconium at birth was brought to the emergency room by his parents because he had no passed stool since they left the hospital. A BE study image is shown. Of the following, what is the most likely diagnosis? A) Diverticulitis B) Intussusception C) Meckel's diverticulum D) Hirschsprung's disease

D) Hirschsprung's disease

A 19-year-old female presents to the emergency room. Over the past two days, she has developed severe abdominal pain associated with bloating of her abdomen. She has been vomiting multiple times and has been unable to pass gas or feces. Physical examination reveals hyperactive and high-pitched bowel sounds. Her past medical history is significant only for a fractured left tibia sustained in a car accident 4 years ago. She is taken to surgery, and a lesion is removed from the terminal ileum. On microscopic examination, pathologist identifies gastric mucosa in the lesion. Of the following, which statement is true regarding her lesion? A) It is due to abdominal trauma sustained in the car accident B) Ileocecal regurgitation produced gastric metaplasia C) It is a significant risk factor for carcinoma D) It is a remnant of the omphalomesenteric duct

D) It is a remnant of the omphalomesenteric duct

A 15-year-old boy presents with pain and swelling about the left knee for the past month. He thought that this condition resulted from an old soccer injury and that it would resolve without incident. The pain, however, has persisted and he is limping. X-rays of the knee demonstrate a "Codman triangle" in the distal femur. Which of the following is the most likely diagnosis? A) Ewing sarcoma B) Giant cell tumor C) Knee sprain D) Osteosarcoma

D) Osteosarcoma

A 45-year-old woman presents to her primary care medical provider with jaundice, pruritus, and periocular and intra-digital xanthomas. Her laboratory results indicate a significantly increased alkaline phosphatase as well as a positive test for antimitochondrial antibodies. The biopsy is shown. The most likely cause of her symptoms is: A) Macronodular cirrhosis. B) Leptospirosis. C) Primary sclerosing cholangitis. D) Primary biliary cholangitis

D) Primary biliary cholangitis

A 56-year-old man was recently diagnosed with early-stage colon cancer. He has no known family history of colon cancer. Which of the following known risk factors is most likely to have contributed to the development of this form of cancer? (A) A diet low in fiber and high in fat (B) Aflatoxin B1 ingestion (C) Helicobacter pylori infection (D) Hepatitis B infection (E) Tobacco and alcohol abuse

The answer is A. A diet low in fiber and high in fat is believed to be a risk factor for the development of colon cancer. Both aflatoxin B1 ingestion and hepatitis B infection are risk factors for hepatocellular carcinoma. Helicobacter pyloriinfection is associated with stomach cancer. Cancers of the mouth, tongue, and esophagus have a marked association with the combined abuse of tobacco and alcohol, as well as HPV infection in a subset of cases

A 10-day-old boy with projectile vomiting and a palpable midepigastric mass most likely has (A) congenital pyloric stenosis. (B) infantile polycystic kidney. (C) intussusception. (D) tracheoesophageal fistula. (E) Wilms tumor.

The answer is A. Congenital pyloric stenosis is an obstruction of the gastric outlet caused by hypertrophy of the pyloric muscularis. The hypertrophic muscle is often perceived as a palpable mass. The principal manifestation of this condition, more common in boys, is projectile vomiting, most often occurring in the first 3 to 6 weeks of life.

A 65-year-old man is seen for the recent onset of jaundice, weight loss, and anorexia. Abdominal examination reveals a distended, palpable gallbladder. Laboratory studies reveal conjugated hyperbilirubinemia, positive urine tests for bilirubin, and total absence of urobilinogen in the urine and stools. The probable diagnosis is (A) adenocarcinoma of the pancreas. (B) amebic abscess of the liver. (C) hepatic vein thrombosis. (D) hepatitis A infection. (E) hereditary spherocytosis.

The answer is A. Conjugated hyperbilirubinemia and positive urine tests for bilirubin are indicative of obstructive jaundice. The further finding of the complete absence of urine and stool urobilinogen indicates total common bile duct obstruction. Additionally, the palpable gallbladder (Courvoisier sign) strongly suggests that the etiology is a malignant tumor, such as adenocarcinoma of the head of the pancreas.

A 4-year-old boy is seen after he suddenly develops a fever, abdominal pain and tenderness, hematuria, and palpable purpuric skin lesions on his buttocks and the extensor surfaces of the arms and legs. The most likely diagnosis is (A) Henoch-Schönlein purpura. (B) idiopathic (immune) thrombocytopenic purpura (ITP). (C) Kawasaki disease. (D) polyarteritis nodosa. (E) thrombotic thrombocytopenic purpura (TTP).

The answer is A. Henoch-Schönlein purpura is an IgA immune complex disease characterized by involvement of small vessels (venules, capillaries, arterioles) with multiple lesions, all about the same age, and is a form of hypersensitivity or leukocytoclastic vasculitis. The disorder may involve only the skin, presenting as palpable purpura, or it may involve a variety of other sites, including the glomeruli, gastrointestinal tract, lungs, or brain.

A 28-year-old woman presents with fever, dysuria, urinary frequency, and flank tenderness. The urine contained numerous neutrophils and many white cell casts. Urine protein was moderately increased. A quantitative urine culture revealed more than 105 bacteria per milliliter. The most likely causative organism is (A) Escherichia coli. (B) Haemophilus influenzae. (C) Neisseria gonorrhoeae. (D) Proteus vulgaris. (E) Pseudomonas aeruginosa.

The answer is A. Organisms involved in urinary tract infections are most often normal flora of the colon, and the most frequent of these is E. coli.The other pathogen that would be likely in this patient is S. saprophyticus, however that was not an answer choice.

A 65-year-old woman with a longstanding history of severe rheumatoid arthritis presents with proteinuria, hypertension, edema, and hypoalbuminemia. Which of the following is the most likely diagnosis? (A) Renal amyloidosis (B) Diabetic nephropathy (C) Membranous glomerulonephritis (D) Minimal change disease (E) Poststreptococcal glomerulonephritis

The answer is A. Renal amyloidosis can occur in both primary and secondary amyloidosis. In the latter, the most frequently occurring underlying illness is rheumatoid arthritis.

A 65-year-old man presents with dysphagia, weight loss, and anorexia. Physical examination is normal. Esophagogastroduodenoscopy with biopsy of an esophageal lesion is performed, revealing squamous cell carcinoma. Which of the following is true regarding this cancer? (A) Cigarette smoking and chronic alcohol use are associated risk factors. (B) Gastroesophageal reflux disease and Barrett esophagus are associated risk factors. (C) Histologic findings include disordered, back-to-back submucosal glands. (D) It most frequently arises in the lower third of the esophagus. (E) This cancer is characterized by an indolent course, and long survival is common.

The answer is A. Squamous cell carcinoma of the esophagus is an aggressive cancer with rapid progression and short survival in all stages of disease. It is most common in subjects with a long-term history of cigarette smoking and alcohol use. The tumor arises most commonly in the upper and middle thirds of the esophagus.

A 25-year-old man presents with hematuria, periorbital edema, hypertension, and hemoptysis. He has also experienced nausea, vomiting, fever, and chills. Serologic testing is positive for antiglomerular basement membrane antibodies. Which of the following is the classic histologic finding in this renal disease? (A) Linear immunofluorescence (B) "Lumpy-bumpy" immunofluorescence (C) "Spike and dome" appearance of the glomerular basement membrane (D) Subendothelial immune complex deposition (E) Tram-track appearance of the glomerular basement membrane on electron microscopy

The answer is A. The clinical description is that of Goodpasture syndrome (antiglomerular basement membrane disease), caused by antibodies directed against antigens in the glomerular and pulmonary alveolar basement membranes. Because antigens are an intrinsic component of the basement membrane, labeled antibodies "paint" the surface of the basement membrane, resulting in the characteristic linear immunofluorescent pattern characteristic of this disorder. "Lumpy-bumpy" immunofluorescence is very coarse, granular immunofluorescence found in poststreptococcal immune complex deposit disease. The tram-track appearance is seen in membranoproliferative glomerulonephritis. The "spike and dome" appearance is seen in membranous glomerulonephritis. Subendothelial immune complex deposition is seen in lupus nephropathy

The illustration is from a liver biopsy of a 34-year-old woman with a long history of alcoholism. Which of the following is the best explanation for the changes shown here? (A) Accumulation of triglycerides within hepatocytes (B) Apoptosis with replacement of damaged cells by lipid-laden macrophages (C) Bilirubin accumulation with mobilization of fat by bile salts (D) Enzymatic fat necrosis with digestion of liver parenchyma by released enzymes (E) Irreversible damage to mitochondria

The answer is A. The figure illustrates fatty change of the liver, which is characterized by the accumulation of intracellular parenchymal triglycerides. It is seen most frequently in the liver, heart, and kidney and is commonly secondary to alcoholism. Fatty change results from an imbalance between the uptake, utilization, and mobilization of fat from liver cells. Alcoholic fatty liver may be reversible with complete abstinence from alcohol.

A 62-year-old man is seen because of a change in bowel habits. A lesion similar to that illustrated below is resected from the sigmoid colon. The diagnosis is (A) adenocarcinoma. (B) Crohn disease. (C) non-Hodgkin lymphoma. (D) pseudomembranous colitis. (E) tubular adenoma.

The answer is A. The illustration demonstrates an adenocarcinoma diffusely infiltrating the wall of the colon, with elevated borders and ulceration of the mucosa.

An elderly woman with chronic constipation dies of a stroke and comes to autopsy. The figure illustrates a portion of her colon. The lesions shown in the figure (A) can be complicated by inflammation, perforation, and peritonitis. (B) are most likely related to a high-fiber diet. (C) most frequently occur high on the right side of the colon. (D) occur most often in teenagers.

The answer is A. The illustration demonstrates diverticulosis of the colon (openings shown by arrows). These lesions are most common in older persons and are found most often in the sigmoid. The incidence of disease is increased in populations that consume low-fiber diets. Although most often asymptomatic, diverticula may become the site of acute inflammation (diverticulitis), sometimes with life-threatening complications, such as perforation and peritonitis.

A pathologist examines a renal biopsy from a 45-year-old man with nephrotic syndrome and requests a Congo red stain to confirm the nature of an amorphous acidophilic extracellular hyaline substance localized within the mesangial matrix of the glomeruli. A positive test confirms the presence of (A) α1-antitrypsin. (B) amyloid. (C) copper. (D) glycogen. (E) hemosiderin.

The answer is B. A positive Congo red test confirms the presence of amyloid. Apple green birefringence is observed under polarized light.

A 60-year-old man presents with proteinuria, hypertension, edema, and hypoalbuminemia. Histologic findings in the glomeruli of his kidneys include mesangial accumulation of basement membrane-like material. Which of the following is the most likely diagnosis? (A) Renal amyloidosis (B) Diabetic nephropathy (C) Membranous glomerulonephritis (D) Minimal change disease (E) Poststreptococcal glomerulonephritis

The answer is B. Diabetic nephropathy is marked by diffuse or nodular mesangial accumulations of glycosylated basement membrane-like material.

For the past week, a 65-year-old woman has been treated for a severe infection with broad-spectrum antibiotics, and she had recovered well. Over the past day, however, she has developed foul-smelling, voluminous, greenish, watery diarrhea, as well as abdominal pain and fever. She is diagnosed with pseudomembranous colitis. Which of the following is the mechanism associated with this condition? (A) Aggregation of bacterial colonies on the lumen, forming pseudomembranes (B) Bacterial release of exotoxin, inducing necrosis of the mucosa (C) Physical invasion of bacteria into the superficial mucosa, leading to pseudomembrane formation (D) Selective killing of C. difficilebacteria by antibiotics (E) Spread of the previous infection to the colon

The answer is B. Pseudomembranous colitis is caused by overgrowth of C. difficile. This organism produces exotoxin that induces necrosis of the superficial mucosa, leading to pseudomembrane formation. The bacteria itself does not invade the mucosa. This condition most often occurs in patients with a history of broad-spectrum antibiotic use, because elimination of normal intestinal flora promotes overgrowth of C. difficile

A 35-year-old man with a known history of severe chronic alcohol abuse presents with low-grade fever, jaundice, hepatomegaly, leukocytosis, and markedly abnormal liver function tests. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) are both elevated. An expected histologic finding in this condition is (A) effacement of the normal liver architecture by diffuse fibrosis and abnormal regenerating nodules. (B) Mallory hyaline inclusions, macrovesicular steatosis, and neutrophilic infiltration. (C) multiple giant cells. (D) nests or cords of well-differentiated cells separated by dense collagen lamellae. (E) parenchymal deposition of hemosiderin.

The answer is B. The clinical picture is that of alcoholic hepatitis, which is characterized by fatty change, focal liver cell necrosis, infiltrates of neutrophils, and intracytoplasmic hyaline inclusions referred to as Mallory bodies

Two weeks after recovery from a severe bout of pharyngitis, an 11-year-old girl is seen because of the acute onset of periorbital edema, hematuria, malaise, nausea, and headache. Which of the following findings is expected? (A) Hypotension (B) Increased antistreptolysin O titer (C) Marked hypoalbuminemia (D) Polyuria (E) Positive urine cultures for β-hemolytic streptococci

The answer is B. The combination of hematuria (with red cell casts), oliguria, azotemia, and hypertension constitutes the nephritic syndrome, the prototype of which is poststreptococcal glomerulonephritis. An indicator of the prior streptococcal infection is an increased titer of antistreptolysin O. Fluid retention is usually minimal, often limited to periorbital edema, and is the result of reduced renal excretion of salt and water, not hypoalbuminemia. Hypertension, not hypotension, is expected. This disorder is an immune complex disorder, and infection of the kidney does not occur *FYI In Mucha's question he has antibodies against Strep group A, but same thing*

A 54-year-old carpenter was brought to the hospital by ambulance after he was involved in a high-speed automobile chase that terminated in a collision into the trunk of a tree. On admission to the hospital, his skin was cold and clammy, his pulse was rapid and thready, and his blood pressure was 60 systolic and 40 diastolic. His blood alcohol was 0.29 g/dL (presumptive level for drunkenness is 0.08). In spite of blood transfusions, he died during an emergency laparotomy that revealed a ruptured spleen and a slightly enlarged liver. Microscopic examination of the liver at autopsy revealed intracytoplasmic clear vacuoles displacing the intact nuclei of the hepatocytes to the periphery of the cells. Special stains will most likely demonstrate that the vacuolar material is (A) bilirubin. (B) fat. (C) glycogen. (D) hemosiderin. (E) water.

The answer is B. The description of clear vacuoles displacing intact nuclei to the periphery is characteristic of fatty change (steatosis) of the liver; however, clear intracytoplasmic vacuolization of hepatocytes may be due to accumulations of water or glycogen, and sometimes special stains are required for confirmation of the nature of the vacuoles. In industrialized countries, such as the United States, the most common cause of fatty change of the liver is alcoholism

A 20-year-old woman with the nephrotic syndrome and slowly progressive impairment of renal function marked by azotemia undergoes a renal biopsy. The patient's response to corticosteroid medication has been unimpressive. The appearance of the biopsy is similar to that shown in the figure. The most likely diagnosis is (A) focal segmental glomerulosclerosis. (B) membranous glomerulonephritis. (C) minimal change disease. (D) poststreptococcal glomerulonephritis. (E) rapidly progressive glomerulonephritis.

The answer is B. The diffuse thickening of the walls of the capillary loops seen in the illustration is characteristic of membranous glomerulonephritis, the most frequent cause of the nephrotic syndrome in young adults. Expected associated findings in this immune complex disease include granular immunofluorescence and a characteristic "spike and dome" appearance that is best visualized with special stains. Intramembranous and epimembranous (subepithelial) electron-dense immune complex deposits are seen by electron microscopy.

A 55-year-old alcoholic man died after an illness characterized by increasing jaundice, ascites, and generalized wasting. Laboratory testing revealed hyperbilirubinemia, hypoalbuminemia, and mildly elevated liver enzymes. The appearance of the liver at autopsy is shown in the figure. The most likely diagnosis is (A) alpha-1-antitrypsin deficiency. (B) cirrhosis. (C) hepatitis A. (D) hepatitis C. (E) multiple metastases.

The answer is B. The figure demonstrates the typical appearance of micronodular cirrhosis, the most common cause of which is alcoholism. Major clinical manifestations include jaundice, ascites, signs of hyperestrinism (palmar erythema, spider telangiectasia, gynecomastia, testicular atrophy), consequences of increased portal venous pressure (esophageal varices, distended abdominal veins [caput medusae], splenomegaly), and consequences of hypoalbuminemia (ascites, peripheral edema).

A 60-year-old woman dies of a tumor that had invaded the renal vein and entered the inferior vena cava. At autopsy, the kidney has the appearance shown in the figure. Which of the following is a characteristic or association of this neoplasm? (A) Adrenal origin (B) Hematuria (C) Hypocalcemia (D) Tumor cells in the urine (E) Typical symmetrical bilateral involvement

The answer is B. The illustration demonstrates a renal cell carcinoma, which most often arises in one of the renal poles, frequently the upper pole. Hematuria is the most frequent presenting sign. The tumor cells often have a clear cell appearance, which led to an earlier erroneous concept that this tumor was of adrenal origin and to the older name "hypernephroma." The tumor is often quite large and may result in a palpable mass. Malignant cells are only rarely detected in the urine in renal cell carcinoma.

A 22-year-old woman presents with fever, malaise, generalized arthralgias, and a skin rash over the nose and malar eminences. Which one of the following possible findings has the greatest relative significance in the overall prognosis for the patient? (A) Atypical verrucous vegetations of the mitral valve (B) Glomerular subendothelial immune complex deposition (C) Immune complexes at the dermalepidermal junction in skin (D) Perivascular fibrosis in the spleen (E) Pleuritis

The answer is B. The overall prognosis in SLE is most closely related to the glomerular lesions in affected patients. These renal lesions are highly variable. In the diffuse proliferative form, almost all of the glomeruli are involved in a marked inflammatory reaction to widespread subendothelial and mesangial immune complex deposition.

A 60-year-old woman presents with deep, achy joint pain in her fingers. She states that the pain gets worse with extensive use of her fingers. Physical examination reveals reduced range of motion and crepitus, with pain noted asymmetrically in the distal interphalangeal (DIP) joints, proximal interphalangeal joints, and metacarpophalangeal joints. Heberden nodes are noted on the DIP joints of one hand. Which of the following is the most likely etiology of this condition? (A) Autoimmune disease (B) Mechanical injury ("wear and tear") (C) N. gonorrhoeae infection (D) Secondary manifestation of chronic lung disease or cyanotic cardiac disease (E) Urate crystal deposition

The answer is B. This is a case of osteoarthritis (degenerative joint disease), the most common form of arthritis. Osteoarthritis is a chronic noninflammatory joint disease most often related to mechanical trauma and long-term use of affected joints ("wear-and-tear" arthritis). Osteoarthritis is characterized by eburnation (polished, ivory-like appearance of bone, due to erosion of overlying cartilage), cystic changes in subchondral bone, and new bone formation. Osteophytes (bony spurs) can form at the distal interphalangeal joints (Heberden nodes) or at the proximal interphalangeal joints (Bouchard nodes)

A 35-year-old man undergoes gastrectomy for gastric carcinoma. Gross examination of the resected stomach reveals diffuse thickening without a discrete mass lesion. Microscopic exam shows an infiltration of signet-ring cells dispersed singly. Family history reveals that his father had a similar cancer at a young age. What gene is most likely to be mutated in this patient and his father? (A) APC (B) CDH1 (C) MSH2 (D) PMS2 (E) p53

The answer is B. This patient most likely has a mutation in CDH1, the gene encoding the cellular adhesion protein E-cadherin. E-cadherin mutations account for a significant proportion of familial gastric cancers and are also implicated in lobular carcinoma of the breast. CDH1-mutated gastric adenocarcinomas typically show signet-ring morphology with diffuse infiltration resulting in a "linitis plastic" ("leather bottle") gross appearance. APC is mutated in the majority of colorectal adenocarcinomas. MSH2 and PMS2 are both mismatch repair genes that may be mutated in Lynch syndrome. Although Lynch syndrome patients are at increased risk for gastric adenocarcinoma, their tumors are typically conventional, rather than signet-ring, in morphology. p53is mutated in a wide variety of sporadic cancers and shows germline mutations in Li Fraumeni syndrome.

In a 44-year-old man with hemoptysis and hematuria, a linear pattern of glomerular immunofluorescence for IgG is observed in a renal biopsy. The most likely associated laboratory finding is a positive test for antibodies directed to (A) streptolysin O. (B) C3 convertase. (C) glomerular basement membranes. (D) hepatitis B virus. (E) Sm (Smith) nuclear antigen.

The answer is C. A linear pattern of glomerular immunofluorescence for IgG is found in Goodpasture syndrome, which is caused by antibodies that react with both glomerular and alveolar basement membranes.

A 50-year-old woman with a 20-year history of type 2 diabetes mellitus presents with proteinuria, hypoalbuminemia, edema, and hyperlipidemia. She has not monitored her serum glucose levels over the past several years. Diabetic nephropathy is diagnosed. What is the classic morphologic finding in diabetic nephropathy? (A) Crescentic formation in glomeruli on light microscopy (B) Intramembranous and epimembranous immune complex deposits in the glomerular basement membrane on electron microscopy (C) Nodular accumulations of mesangial matrix on light microscopy (D) Sclerosis within capillary tufts that involves only some glomeruli and only parts of affected glomeruli on light microscopy (E) Wire-loop abnormalities from immune complex deposits and thickening of the glomerular basement membrane on light microscopy

The answer is C. Diabetic nephropathy manifests clinically as the nephrotic syndrome; however, this syndrome is compounded by renal failure and hypertension. Ultrastructural changes include a marked increase in the thickness of the glomerular basement membrane and mesangial accumulation of glycosylated basement membranelike material. Light microscopy findings include diffuse glomerulosclerosis (a diffuse increase in mesangial matrix) and nodular glomerulosclerosis (nodular accumulations of mesangial matrix).

A 5-year-old boy presents with hematuria. His mother states that he has had a sore throat for the past 2 days and that he has had hematuria a few times in the past, also concomitantly with a sore throat. She states that his urine usually returns to a normal clear yellow color after a few days. Which of the following is the most likely diagnosis? (A) Alport syndrome (B) Goodpasture syndrome (C) IgA nephropathy (D) Membranoproliferative glomerulonephritis (E) Poststreptococcal glomerulonephritis

The answer is C. IgA nephropathy is the most common glomerular disease and is defined by mesangial deposition of IgA. In its most typical form, the clinical manifestations are limited to a few days of hematuria following an infection; however, there are many etiologic factors, and the condition can vary from one of little import to a severe form of renal disease

A 60-year-old man presents with hematemesis, melena, guaiac-positive stools, and signs of circulatory collapse. He has a 20-year history of burning midepigastric pain and tenderness relieved by food, milk, or antacids. Also, he has been taking high doses of NSAIDs to relieve the pain of long-standing arthritis. Esophagogastroduodenoscopy reveals a peptic ulcer in the upper duodenum. Which of the following is an important association of duodenal peptic ulcer disease? (A) Barrett esophagus and columnar intestinal metaplasia of esophageal squamous epithelium (B) Evolution into carcinoma as a likely sequela (C) H. pylori infection (D) Hiatal hernia and incompetent lower esophageal sphincter (E) Pernicious anemia and achlorhydria

The answer is C. Of course, the immediate problem in this patient is life-threatening upper gastrointestinal hemorrhage, an important complication of peptic ulcer disease. Peptic ulcer disease occurs most frequently in the first portion of the duodenum, the lesser curvature of the stomach, or the distal esophagus. Duodenal peptic ulcers are associated with hypersecretion of gastric acid and pepsin and are closely related to gastric H. pylori infection. Apparently, H. pylori increases gastric acid secretion and impairs mucosal defenses. Other predisposing factors include aspirin or NSAID intake, smoking, Zollinger Ellison syndrome, primary hyperparathyroidism, and multiple endocrine neoplasia type I.

A 45-year-old man with a long history of alcoholism presents with severe epigastric pain, nausea, vomiting, fever, and an increase in serum amylase. During a previous hospitalization for a similar episode, computed tomography scanning demonstrated calcifications in the pancreas. A diagnosis of acute pancreatitis superimposed on chronic pancreatitis was made. In this condition, which of the following types of necrosis is most characteristic? (A) Caseous (B) Coagulative (C) Enzymatic (D) Fibrinoid (E) Liquefactive

The answer is C. Pancreatic enzymatic fat necrosis represents autodigestion by proteolytic and lipolytic enzymes released from damaged parenchymal cells of the pancreas. Fatty acids liberated by the digestion of fat form calcium soaps, a process referred to as saponification. The precipitated calcium in the soaps can be visualized by radiologic imaging.

Upper and lower gastrointestinal endoscopic examinations are performed on a 45-year-old man. A lesion is found and the patient is told that the lesion has NO malignant potential. Of the following choices, which is the lesion that was most likely found? (A) Colorectal villous adenoma (B) Crohn disease (C) Duodenal peptic ulcer (D) Familial multiple polyposis (E) Ulcerative colitis

The answer is C. Peptic ulcer of the duodenum is not a precursor lesion to carcinoma. The risk of malignant transformation in familial multiple polyposis approaches 100%. Colorectal villous adenomas undergo malignant change in about 30% of cases. There is a markedly increased incidence of colon cancer in long-standing cases of ulcerative colitis. The incidence of colon cancer is also increased in Crohn disease, but to a lesser degree than in ulcerative colitis

A 45-year-old woman presents to her primary care physician with jaundice, pruritus, and periocular and intradigital xanthomas. Her laboratory results indicate a significantly increased alkaline phosphatase as well as a positive test for antimitochondrial antibodies. The most likely cause of her symptoms is (A) leptospirosis. (B) macronodular cirrhosis. (C) primary biliary cirrhosis. (D) primary sclerosing cholangitis. (E) secondary biliary cirrhosis.

The answer is C. Primary biliary cirrhosis is an autoimmune condition that typically presents in middle-aged women. The itching and hypercholesterolemia are secondary to severe obstructive jaundice. Leptospirosis is a condition caused by a treponemal bacterium that results in jaundice, renal failure, and hemorrhagic phenomena. Macronodular cirrhosis is usually a result of hepatitis B or hepatitis C infection. Primary sclerosing cholangitis is associated with ulcerative colitis and with an increased incidence of cholangiocarcinoma. Secondary biliary cirrhosis is caused by extrahepatic biliary obstruction.

A 56-year-old man who had been receiving intravenous antibiotics for severe cellulitis develops fever, toxicity, and severe diarrhea. This scenario suggests which of the following disorders? (A) Celiac sprue (B) CMV infection (C) Pseudomembranous colitis (D) Ulcerative colitis (E) Whipple disease

The answer is C. Severe diarrhea, fever, and toxicity following broad-spectrum antibiotic therapy is likely due to pseudomembranous colitis. This disorder is caused by overgrowth of Clostridium difficile,a commensal microorganism indigenous to the bowel, and is marked morphologically by superficial mucosal erosions with overlying necrotic, loosely adherent mucosal debris. The clostridia remain intraluminal, but secrete an enterotoxin that is responsible for the clinical and pathologic manifestations of the disorder

A 3-year-old girl presents with generalized edema shortly after recovery from an upper respiratory infection. Laboratory studies reveal marked albuminuria, as well as hypoalbuminemia and hyperlipidemia. Prior similar episodes responded to adrenal steroid medication. The most likely diagnosis is (A) focal segmental glomerulosclerosis. (B) membranous glomerulonephritis. (C) minimal change disease. (D) poststreptococcal glomerulonephritis. (E) rapidly progressive glomerulonephritis.

The answer is C. The combination of generalized edema, massive proteinuria, hypoalbuminemia, and hyperlipidemia constitutes the nephrotic syndrome, the prototype of which is minimal change disease (lipoid nephrosis). This disorder characteristically occurs in young children and demonstrates intracytoplasmic lipid in the proximal convoluted tubules, a paucity of glomerular abnormalities by light microscopy, and "fusing" (absence) of the epithelial foot processes by electron microscopy

A 50-year-old man with hypertension and the nephrotic syndrome undergoes a renal biopsy. The appearance of the biopsy is similar to that shown in the figure. Of the following possible additional laboratory findings, which one is most characteristically associated with this lesion? (A) Decreased creatinine clearance (B) Fixed specific gravity of urine (C) Hyperglycemia (D) Hypocalcemia (E) Increased blood urea nitrogen

The answer is C. The illustration shows nodular glomerulosclerosis (Kimmelstiel-Wilson nodules), the most characteristic glomerular finding in diabetes mellitus. The nodules are accumulations of mesangial matrix-like material.

A 20-year-old man presents with severe right lower quadrant abdominal pain, nausea, and anorexia. He states that the abdominal pain started around his umbilicus and has now migrated to the right lower quadrant of his abdomen. Physical examination reveals exquisite tenderness at McBurney point (the point one-third of the distance along the line from the right anterior superior iliac spine to the umbilicus). This patient is diagnosed with acute appendicitis. Which of the following is the treatment for this condition? (A) Antibiotics only, because the appendix is crucial for survival (B) Surgical resection of the appendix, because appendicitis can lead to appendiceal cancer (C) Surgical resection of the appendix, because appendicitis can lead to perforation or abscess (D) "Watch-and-wait" approach over days to see if inflammation subsides

The answer is C. The inflamed appendix in acute appendicitis should be surgically removed because of possible devastating complications of perforation or abscess.

A 55-year-old woman has cirrhosis. Twenty years ago she received a blood transfusion for profuse bleeding associated with a complication of childbirth. Shortly thereafter, she had an acute disease diagnosed as non-A, non-B hepatitis. Throughout her lifetime, her alcohol consumption has been minimal. Which of the following viruses is most likely responsible for her past and current liver disease? (A) Hepatitis A (B) Hepatitis B (C) Hepatitis C (D) Hepatitis D (E) Hepatitis E

The answer is C. The most frequent cause of transfusion-related hepatitis is hepatitis C virus infection. Hepatitis C virus is the most frequent cause of what was formerly termed non-A, non-B hepatitis.

A diagnosis of acute hematogenous osteomyelitis is made in a 5-year-old boy who had presented with the sudden onset of a high fever. He had been limping and had had erythema, edema, and pain around his right knee for several days. Which of the following is true of this condition? (A) It occurs with peak incidence in the elderly. (B) It most commonly affects the iliac crests. (C) Surgical incision and drainage is almost always required. (D) It is most commonly caused by Staphylococcus aureus. (E) It is more common in females.

The answer is D. Acute hematogenous osteomyelitis occurs with peak incidence in children, most commonly affects the metaphyses of long bones, and is more common in boys. In the acute stage, pyogenic osteomyelitis often resolves with antibiotic therapy. If the disorder is allowed to progress to necrosis and sequestrum formation, surgical intervention is usually required.

A 73-year-old man develops severe, intractable diarrhea during hospitalization for bacterial pneumonia caused by a multidrug-resistant organism. What organism is most likely responsible for his gastrointestinal symptoms? (A) MRSA (B) Streptococcus pneumoniae (C) Candida (D) Clostridium difficile (E) Clostridium botulinum

The answer is D. C. difficile causes diarrhea in patients in whom competing colonic flora has been obliterated by antibiotics. Candidal infections are also common in patients on antibiotics but typically manifest with oral or vaginal candidiasis, rather than diarrhea. MRSA is a growing problem both in the hospital and in the community but does not typically cause diarrhea (although it could well be the cause of the patient's drug-resistant pneumonia!). C. botulinum causes botulism, a rare but sometimes fatal paralytic disorder, and is not associated with diarrhea.

A 25-year-old man presents with lowgrade fever, weight loss, fatigue, crampy abdominal pain, episodic diarrhea, and postprandial bloating. Right lower quadrant tenderness is elicited on palpation of the abdomen. A capsule endoscopy reveals thickening of the terminal ileum, edema, marked luminal narrowing, and a cobblestone appearance of the mucosa. Which of the following is a characteristic of this condition? (A) Additional typical findings include crypt abscesses and pseudopolyps. (B) Inflammation and ulceration limited to mucosa and submucosa with sparing of deeper layers. (C) It can affect any portion of the gastrointestinal tract, but proximal jejunum is most common site of involvement. (D) It can cause fistula formation between loops of affected bowel. (E) It is a benign, self-limited disorder with no complicating sequelae.

The answer is D. Crohn disease and ulcerative colitis are the two classic inflammatory bowel diseases. Crohn disease is a chronic inflammatory condition that can affect any part of the gastrointestinal tract from mouth to anus, but most commonly involves the distal ileocecum, small intestine, or colon. Morphologically, Crohn disease manifests as transmural inflammation (involving all layers of the intestinal wall), thickening of involved intestine, linear ulceration, a cobblestone appearance, skip lesions (normal intestine between affected regions), and granulomas. Strictures and fistulae may develop, leading to intestinal obstruction. Crohn disease may lead to carcinoma of the small intes-tine or colon, but much less commonly than ulcerative colitis.

A 25-year-old man presents with generalized edema. Blood tests reveal severe proteinuria, hypoalbuminemia, and hyperlipidemia. The patient does not respond well to a course of corticosteroids. A renal biopsy demonstrates findings indicative of focal segmental glomerulosclerosis. Which of the following best describes the histologic findings in this disorder? (A) Crescentic formation in glomeruli on light microscopy (B) Intramembranous and epimembranous immune complex deposits in the glomerular basement membrane on electron microscopy (C) Nodular accumulations of mesangial matrix material on light microscopy (D) Sclerosis within capillary tufts that involves only some glomeruli and only parts of affected glomeruli on light microscopy (E) Wire-loop abnormalities from immune complex deposits and thickening of the glomerular basement membrane on light microscopy

The answer is D. Focal segmental glomerulosclerosis has clinical manifestations similar to minimal change disease, but it tends to occur in older patients and does not respond well to steroid treatment. Glomerular hyaline sclerosis occurs in a focal (some, but not all, glomeruli) and segmental (only part of an affected glomerulus) distribution.

A 68-year-old woman has fever, generalized lower abdominal pain, and bright red blood in the stools. The white blood cell count is 15,000/mL, with 85% segmented neutrophils. The most likely diagnosis is (A) acute appendicitis. (B) carcinoma of the rectum. (C) Crohn disease. (D) diverticulitis. (E) tubular adenoma in sigmoid colon.

The answer is D. Generalized lower abdominal pain, bloody stools, and signs of acute inflammation in an older patient are classic findings in diverticulitis. Appendicitis and Crohn disease occur more often in younger persons, and bloody stools would not be expected. Signs of acute inflammation would not be expected in carcinoma of the rectum or in tubular adenoma.

A 60-year-old woman develops a rightsided colonic adenocarcinoma. She has a history of alleged colonoscopies; however, review of images from her most recent colonoscopy reveals a prominent fold in the region that subsequently developed cancer. Biopsy from this area would have most likely revealed which of the following? (A) Tubular adenoma (B) Hyperplastic polyp (C) Peutz-Jeghers polyp (D) Sessile serrated adenoma (E) Inflammatory polyp

The answer is D. Sessile serrated adenomas can be very subtle and are easily missed on endoscopy. Under the microscope, they closely resemble hyperplastic polyps but show more complicated glands, often with "boot-shaped" configurations at the gland bases. Unlike tubular adenomas, they lack the overtly dysplastic epithelium and often do not form polypoid lesions. Hyperplastic polyps, Peutz-Jeghers polyps, and inflammatory polyps are not malignant precursors.

A 63-year-old chronic alcoholic presents with weight loss, anorexia, and abdominal pain radiating to the back. Physical examination indicates a palpably enlarged gallbladder, and laboratory studies demonstrate conjugated hyperbilirubinemia. Computed tomography demonstrates a mass in the head of the pancreas. Which of the following is associated with the diagnosis of pancreatic adenocarcinoma? (A) Asterixis (B) Gallstone ileus (C) Murphy sign (D) Trousseau sign (E) Whipple triad

The answer is D. The Trousseau sign, or migratory thrombophlebitis, is associated with carcinoma of the pancreas. The finding of appearing and disappearing thrombosis can affect up to 10% of patients. Only about 20% of lesions are in the head of the pancreas, where they present relatively early with obstructive jaundice. Asterixis is a flapping tremor associated with hepatic encephalopathy. Gallstone ileus is a complication of cholelithiasis when the gallstone erodes through the gallbladder into the adjacent small bowel. The Murphy sign is associated with acute cholecystitis. The Whipple triad is associated with insulinomas, tumors of the endocrine (rather than exocrine) pancreas.

A 54-year-old man presents with multiple recurrent peptic ulcers of the duodenum and the jejunum. Gastric acid secretion is refractory to proton pump inhibitors. These findings suggest an underlying (A) adenocarcinoma of the pancreas. (B) adenoma of the adrenal medulla. (C) carcinoid of the jejunum. (D) islet cell tumor of the pancreas. (E) pheochromocytoma.

The answer is D. The Zollinger-Ellison syndrome, characterized by markedly increased gastric acid production and intractable peptic ulcer, is caused by hypersecretion of a gastrin-producing islet cell tumor (gastrinoma).

A 5-year-old boy diagnosed with poststreptococcal glomerulonephritis was admitted to the hospital several weeks ago. Over the last several weeks, his clinical state has not improved. Severe oliguria has developed, his serum creatinine has continued to rise, and his glomerular filtration rate has decreased by 50% since his admission to the hospital. Which of the following is the most likely diagnosis? (A) Alport syndrome (B) Membranoproliferative glomerulonephritis (C) Membranous glomerulonephritis (D) Rapidly progressive glomerulonephritis (E) Renal papillary necrosis

The answer is D. The clinical description is that of RPGN, which is defined as the nephritic syndrome that progresses rapidly to fulminant renal failure within weeks or months. RPGN is classified into three categories: antiglomerular basement membrane (anti-GBM) antibody disease, immune complex deposit disease, and pauciimmune disease (ANCApositive). Characteristic histologic findings in RPGN include crescents between the Bowman capsule and the glomerular tuft. In approximately 50% of cases of RPGN, the disease is of poststreptococcal etiology. It should be noted, however, that the most common outcome of poststreptococcal glomerulonephritis is complete recovery, and only a small minority of patients progress to RPGN.

A glomerular immunofluorescent pattern for IgG similar to that shown in the figure would be expected in which of the following patients? (A) A 3-year-old girl with recurrent bouts of the nephrotic syndrome (B) A 9-year-old boy with "smoky" urine 2 weeks after recovery from a streptococcal infection (C) An 18-year-old woman with nephrotic syndrome and progressive chronic renal disease (D) A 25-year-old man with hemoptysis and hematuria (E) A 26-year-old woman with a "butterfly" rash

The answer is D. The illustration demonstrates linear immunofluorescence, which is characteristic of disease caused by antiglomerular basement membrane antibodies. In Goodpasture syndrome, antibodies directed against antigens in the basement membranes of the glomeruli as well as the pulmonary alveoli result in both hemorrhagic pneumonitis with hemoptysis and glomerular disease with hematuria.

In a routine colonoscopy, a 76-year-old man is found to have a lesion similar to that shown in the illustration. The lesion shown is a classic example of which of the following? (A) Hamartoma (B) Invasive adenocarcinoma (C) Peutz-Jeghers polyp (D) Tubular adenoma (E) Villous adenoma

The answer is D. The illustration shows a tubular adenoma, which is the most common form of adenomatous polyp. These lesions can be single or multiple, or they can occur as components of various multiple polyposis syndromes. Notable among these syndromes are Gardner (associated with osteomas and soft tissue tumors), Turcot (associated with central nervous system tumors), and FAP. All of the foregoing are associated with an increased incidence of colon malignancy. In contrast, the Peutz-Jeghers polyp is a nonneoplastic hamartomatous lesion. Even though the polyp itself does not transform into colon cancer, the Peutz-Jeghers syndrome is associated with an increased incidence of colon cancer and malignancies elsewhere.

A 15-year-old boy presents with a pathologic fracture following a minor injury on the soccer field. The area of fracture is surrounded by a large tumor which shows marked pleomorphism, high mitotic activity, and extensive cartilaginous differentiation on microscopy. The most likely diagnosis is (A) giant cell tumor. (B) osteochondroma. (C) chondrosarcoma. (D) osteosarcoma. (E) Ewing sarcoma.

The answer is D. This question illustrates an important point: in young patients, bone malignancies showing prominent cartilaginous differentiation are almost assuredly chondroblastic osteosarcomas, rather than chondrosarcomas. Conventional chondrosarcomas occur almost exclusively in older patients.

A 70-year-old man presents with fatigue, weight loss, abdominal pain, and overt blood in the stools. A complete blood count reveals anemia with hemoglobin of 10.0 g/dL. A colonoscopy and colon biopsy reveal adenocarcinoma. Which of the following is the most likely predisposing lesion that led to this condition? (A) FAP syndrome (B) Hyperplastic polyp (C) Long-standing ulcerative colitis (D) Peutz-Jeghers polyp (E) Tubular adenoma

The answer is E. Adenocarcinoma of the colon most commonly develops through a progression of mutations in oncogenes and tumor suppressor genes in a multistep process. Normal mucosa evolves into a tubular adenoma with malignant potential, which then further evolves into carcinoma (the adenoma-carcinoma sequence). Carcinoma of the rectosigmoid (left-sided) tends to present as early obstruction, with change in bowel habits and decreased caliber of stool, whereas carcinoma of the right colon (right-sided) tends to present late, with iron deficiency anemia due to chronic blood loss from the lesion.

A 4-year-old boy presents with severe proteinuria, hypoalbuminemia, generalized edema, and hyperlipidemia. The patient improves on an empiric trial of corticosteroids, with complete resolution of proteinuria. Which of the following is the most likely diagnosis? (A) Diabetic nephropathy (B) Focal segmental glomerulosclerosis (C) Lupus nephropathy (D) Membranous glomerulonephritis (E) Minimal change disease

The answer is E. Minimal change disease (lipoid nephrosis) is the prototype of the nephrotic syndrome in children, who usually respond well to steroid therapy. Minimal change disease is characterized grossly by lipid-laden renal cortices. Light microscopy reveals normal glomeruli, but electron microscopy demonstrates the fusion of epithelial foot processes.

A renal biopsy taken from a 23-year-old woman with nephrotic syndrome prominently features glomerular immune complex deposits. Of the following disorders that affect the glomerulus, which is suggested by the findings? (A) Amyloidosis (B) Diabetic nephropathy (C) IgA nephropathy (D) Minimal change disease (lipoid nephrosis) (E) Membranous glomerulonephritis

The answer is E. Of the choices listed, only membranous glomerulonephritis is an immune complex disease.

A 32-year-old woman was evaluated for severe watery diarrhea. Diagnostic testing revealed achlorhydria and reduced concentrations of serum potassium. Imaging studies revealed the presence of a pancreatic tumor. Special stains will most likely reveal the pancreatic tumor to be which of the following? (A) Alpha-cell tumor (glucagonoma) (B) Beta-cell tumor (insulinoma) (C) Gastrinoma (D) Somatostatinoma (E) VIPoma

The answer is E. The VIPoma is an islet cell tumor of the pancreas that is associated with Watery Diarrhea, Hypokalemia, and Achlorhydria (WDHA syndrome or Verner-Morrison syndrome), all caused by the secretion of vasoactive intestinal peptide (VIP) by the tumor.

A 5-year-old boy presents with "teacolored urine," oliguria, and periorbital edema. He had a sore throat 2 weeks ago that had resolved before his parents sought medical treatment. The patient is found to be hypertensive. Urea nitrogen and creatinine are elevated. Antistreptolysin O titer and anti-DNAase B titer are also elevated. Urine tests are positive for blood and red cell casts. Which of the following is the most likely mechanism for this patient's condition? (A) Acute bacterial infection of the kidneys (B) Amyloid deposits (C) ANCA-positive vasculitis (D) Antibody against glomerular basement membrane antigens (E) Immune complex deposits

The answer is E. The clinical description is that of poststreptococcal glomerulonephritis, the prototype of the nephritic syndrome. An antecedent infection, usually of the pharynx or skin, with a group A β-hemolytic streptococcus occurs approximately 1 to 2 weeks before the onset of the renal manifestations. Poststreptococcal glomerulonephritis is an immune complex disease, with antigen-antibody-complement complexes localizing to the outside (subepithelial side) of the glomerular basement membrane. An intense inflammatory response is elicited, including chemotactic attraction of neutrophils, release of lysosomal enzymes, partial destruction of basement membrane, and bleeding into the Bowman space

A 16-year-old boy presents with a 24-hour history of severe abdominal pain, nausea, vomiting, and low-grade fever. The pain is initially periumbilical in location but has migrated to the right lower quadrant of the abdomen, with maximal tenderness elicited at a site one-third of the way between the crest of the ileum and the umbilicus (McBurney point). The leukocyte count is 14,000/mm3, with 74% segmented neutrophils and 12% bands. Surgery is performed. Which of the following describes the expected findings at the affected site? (A) Fistula (abnormal duct or passage) connecting to the abdominal wall (B) Granulation tissue (new vessels and young fibroblasts) with a prominent infiltrate of eosinophils (c) Granulomatous inflammation with prominent aggregates of epithelioid cells and multinucleated giant cells (d) Massive infiltration of lymphocytes and plasma cells (e) Prominent areas of edema, congestion, and a purulent reaction with localized areas of abscess formation

The answer is E. The clinical findings are typical of acute appendicitis, another example of severe acute inflammation. Because the danger of perforation is great, early appendectomy is the treatment of choice. Suppurative or purulent inflammation is characterized by the prominent areas of edema resulting from increased vascular permeability, congestion, and a purulent (pus-containing) exudate consisting of necrotic cells and large numbers of neutrophils. In addition, other signs of acute inflammation, such as congestion, are prominent. The patient responds with the sensation of pain (induced by increased hydrostatic pressure in tissue and by chemical mediators such as bradykinin) and the acute phase reaction (in this instance, fever and neutrophilic leukocytosis with a "shift to the left").

A 69-year-old man was seen for vague abdominal distress. The gastric lesion shown in the figure was resected following initial endoscopic discovery. Which of the following statements about this condition is correct? (A) It has been decreasing in frequency over the past several decades. (B) It is more frequent in Japan than in the United States. (C) It is related to the use of nitrites as food preservatives. (D) It may result in Krukenberg tumors. (E) It will most likely heal with conservative management.

The answer is E. The illustration shows a chronic gastric peptic ulcer with characteristic radiating folds of the gastric mucosa starting at the ulcer margins. The lesion has a smooth base with a little fibrin attached and nonelevated, punched-out margins, in contrast to gastric carcinoma, which often has an irregular necrotic base and firm, raised margins. Despite these characteristic findings, the distinction between gastric peptic ulcer and ulcerated carcinoma must be established by biopsy. In contrast to carcinoma, peptic ulcer will usually heal with conservative management.

The most likely diagnosis in a 24-year old woman with the nephrotic syndrome, progressive azotemia, and thickening of glomerular capillary loops apparent on light microscopy is (A) Alport syndrome. (B) diabetic nephropathy. (C) focal segmental glomerulosclerosis. (D) lipoid nephrosis. (E) membranous glomerulonephritis

The answer is E. The observation of thickened glomerular capillary loops apparent on light microscopy permits the diagnosis of membranous glomerulonephritis. This condition is most frequent in young women and is characterized clinically by the nephrotic syndrome and progressive azotemia.

A 45-year-old man complains of "heartburn" and burning epigastric pain, relieved by antacids and triggered by eating spicy or acidic foods or by assuming a recumbent position. The patient smokes two packs of cigarettes a day and consumes several alcoholic drinks each evening. Which of the following is the usual cause of this patient's condition? (A) Columnar intestinal metaplasia of esophageal squamous epithelium (B) Excessive acid production in the stomach (C) Excessive NSAID use (D) H. pylori infection (E) Hiatal hernia and incompetent lower esophageal sphincter

The answer is E. This is a classic case of GERD, which is caused by reflux of gastric acid contents into the lower esophagus. GERD manifests as burning epigastric pain on eating spicy foods or on lying recumbent. The pain is usually relieved by antacids. GERD is most commonly associated with hiatal hernia and an incompetent lower esophageal sphincter, as well as with excessive use of alcohol or tobacco, increased gastric volume, pregnancy, and scleroderma. Barrett esophagus, or columnar intestinal metaplasia of the epithelium of the distal esophagus, is a complication of long-standing GERD

A 25-year-old woman experiences the sudden onset of fever, chills, right flank pain, and right-sided costovertebral angle tenderness. Her urinary sediment contains numerous gram-negative bacilli. Which of the following additional urinary findings would help establish the likely diagnosis? (A) Broad waxy casts (B) Decreased protein (C) Decreased volume (D) Red cell casts (E) White cell casts

The answer is E. This is a classic case of acute pyelonephritis, an acute infection of the renal parenchyma. White cell casts in the urine are pathognomonic of acute pyelonephritis. Although microscopic hematuria is a frequent finding in acute pyelonephritis and other urinary tract infections, red cell casts are not seen since the glomeruli tend to be spared in renal infection. Red cell casts are a specific indicator of glomerular inflammation.

In the diagnostic workup of a 42-year old man with chronic malabsorption and diarrhea, bacillary forms within periodic acid Schiff (PAS)-positive macrophages in the lamina propria of the small intestinal mucosa were demonstrated by electron microscopy. This finding is characteristic of (A) celiac disease. (B) Crohn disease. (C) disaccharidase deficiency. (D) tropical sprue. (E) Whipple disease.

The answer is E. Whipple disease, a systemic illness almost always involving the small intestine, is characterized morphologically by distinctive PAS-positive macrophages within affected organs. On electron microscopy, the PAS-positive material is seen to consist of numerous bacillary forms of the gram-positive actinomycete Tropheryma whippelii. The disorder responds to a number of antibacterial agents, but without therapy the course is usually progressive and fatal.