USMLE题库Hepatic21-30-4-6

1、Hepatic题库Q 21A 58-year-old Caucasian male is found to have diffuse gallbladder calcification as an incidental finding on abdominal X-ray. He denies any history of severe abdominal pain or jaundice. His vital signs are stable and physical examination is unremarkable. You inform the patient that:A. It

2、 is a benign finding with no risk of serious disease B. The finding is typically associated with fluke infection of the biliary tree C. The patient is at high risk of acute cholecystitis D. The patient is at high risk of gallbladder cancer E. The patient should be worked up for colon cancerA 21Corre

3、ct answer:DThis abdominal radiograph contains the classic finding of a “porcelain gallbladder,”a term used to describe the bluish, brittle, calcium-laden gallbladder wall that can develop in some patients with chronic cholecystitis. The porcelain gallbladder is typically diagnosed on radiograph, som

4、etimes incidentally, by a rim of calcium deposits that outline the gallbladder The pathogenesis of the condition remains unclear, but it is thought that calcium salts are deposited intramurally secondary to either chronic irritation from gallstones or as a component of the natural progression of chr

5、onic inflammation. Although patients are often asymptomatic, some may present with right upper quadrant pain or with a firm, nontender mass in the right upper quadrant. Cholecystectomy is recommended for those with porcelain gallbladders because 11-33% of this patient population will eventually deve

6、lop gallbladder carcinoma.(Choice A) It would be entirely inaccurate to advise this patient that porcelain gallbladder is a benign finding with no risk of serious disease.(Choice B) Fluke infection of the biliary tree is associated with the formation of brown pigment stones, not porcelain gallbladde

7、r.(Choice C) Cholelithiasis, not porcelain gallbladder, is a risk factor for acute cholecystitis.(Choice E) Porcelain gallbladder is associated with carcinoma of the gallbladder, not carcinoma of the colon. Educational Objective:Cholecystectomy is recommended for those with porcelain gallbladders be

8、cause 11-33% of this patient population will eventually develop gallbladder carcinoma.Q 22A 20-year-old male has noticed several episodes intermittent self-resolving jaundice. There is no particular association with his symptoms. He is otherwise healthy and has no other symptoms. He does not use tob

9、acco, alcohol or drugs. Complete blood count is with in normal limits.Liver studiesAlbumin4.0 mg/dLTotal protein, serum 6.5 g/dLTotal bilirubin2.8mg/dLDirect bilirubin2.0 mg/dLAlkaline phosphatase90 U/LAspartate aminotransferase (SGOT)28 U/LAlanine aminotransferase (SGPT)30 U/LLiver biopsy shows abu

10、ndant pigment inclusions in the lysosomes of the otherwise normal hepatocytes. Electron spin resonance spectroscopy reveals that the pigment is composed of polymers of epinephrine metabolites. Which of the following is the most likely cause of his jaundice? A.Increased production of catecholaminesB.

11、Defective hepatocellular excretion of bilirubin glucuronidesC.Ineffective intramedullary erythropoiesisD.Impaired conjugation of bilirubinE.Low serum ceruloplasminA 22Correct answer:BDubin-Johnson syndrome is characterized by a defect in the hepatic excretion of bilirubin glucuronides across the can

12、alicular membrane. Individuals with this rare, benign condition have predominantly conjugated chronic hyperbilirubinemia that is not associated with hemolysis. Grossly，the liver is strikingly black. Histological features are normal, though a dense pigment composed of epinephrine metabolites within t

13、he lysosomes can be see门.Clinically, icterus is evident, though the physical examination is typically otherwise normal. Most patients are asymptomatic, with some complaining of nonspecific issues (eg, fatigue, abdominal pain, weakness). The icterus may be so mild as to only become evident in the con

14、text of a trigger such as illness, pregnancy, or oral contraceptive usage. Routine laboratory testing is unremarkable, including the complete blood count and liver function profile. Serum bilirubin levels usually range from 2-5 mg/dL but can also be normal or extremely elevated (20-25 mg/dL).For the

15、 diagnosis of Dubin-Johnson syndrome to be made, conjugated hyperbilirubinemia with a direct bilirubin fraction of at least 50% and an otherwise normal liver function profile must be present. Confirmation can be obtained by evaluating the urinary coproporphyrin for unusually high levels of coproporp

16、hyrin I.Because this condition is benign, no treatment is necessary and the prognosis is excellent.(Choice A) Increased production of catecholamines is not associated with Dubin-Johnson syndrome, despite the hepatocyte accumulation of epinephrine metabolites in this condition.(Choice C) Ineffective

17、intramedullary erythropoiesis is seen in conditions such as beta-thalassemia and myelodysplasia，not Dubin-Johnson syndrome. (Choice D) Impaired bilirubin conjugation is seen in conditions such as Crigler-Najjar syndrome and Gilbert syndrome, not Dubin-Johnson syndrome.(Choice E) Extremely low or abs

18、ent levels of serum ceruloplasmin are seen in Wilson disease and aceruloplasminemia, not Dubin-Johnson syndrome.Educational Objective:Dubin-Johnson syndrome is characterized by a defect in the hepatic excretion of bilirubin glucuronides across the canalicular membrane. Grossly, the liver is striking

19、ly black. Histological features are normal, though a dense pigment composed of epinephrine metabolites within the lysosomes can be seen.Q 23A 54-year-old Caucasian male with two-year history of stable alcoholic cirrhosis experiences progressive abdominal distention, malaise and anorexia despite comp

20、lete abstinence from alcohol. He has a prior history of intravenous drug use. His serum alpha-fetoprotein level (AFP) has increased substantially over the last six months. This patient most likely suffers from: A.Viral hepatitis B.Hemochromatosis C.Wilsons disease D.a 1-antitrypsin deficiency E.Hepa

21、tic abscess F. Hepatocellular adenoma G.Hepatocellular carcinomaA 23Correct answer:CThe three major etiologies of hepatocellular carcinoma (HCC) are viral infection with hepatitis B or C, chronic alcoholism, and the consumption of food contaminants such as aflatoxins. The development of cirrhosis, w

22、hile not required, appears to be a major contributor to the appearance of this hepatic neoplasm. Diagnosis of hepatocellular carcinoma can be challenging, as the clinical manifestations of HCC overlap with those of cirrhosis or chronic hepatitis; most patients complain of upper abdominal pain, malai

23、se, fatigue, weight loss, and sometimes a sensation of abdominal fullness. Because elevated serum alpha-fetoprotein (AFP) is present in 50-75% of patients with HCC, monitoring the trend of AFP levels can be helpful in distinguishing cirrhosis from HCC.As the primary hepatocellular carcinoma enlarges

24、, it typically will either metastasize to another site or cause deterioration of hepatic function. Patients with stable, compensated cirrhosis who suddenly decompensate without apparent reason should be carefully evaluated for hepatocellular carcinoma, especially if serum AFP levels are elevated (as

25、 in this case).(Choice A) Patients with hepatitis C infection can also have slightly elevated alpha-fetoprotein levels but continuous rise should alert more towards the hepatocellular carcinoma.(Choice B) Hemochromatosis is an autosomal recessive disease characterized by abnormally high iron absorpt

26、ion that results in iron overload. Common clinical manifestations include liver disease, hyperpigmentation, diabetes mellitus “bronze diabetes”), impotence, arthropathy, and cardiac enlargement. Laboratory findings include mildly elevated liver function tests, elevated plasma iron with more than 50%

27、 saturation of transferrin, and elevated serum ferritin.(Choice D) Produced primarily in the liver, a 1-antitrypsin (A1AT) is a serum protein that inhibits several different proteolytic enzymes (eg, pancreatic trypsin, chymotrypsin, neutrophil elastase). Deficiency of this protein is associated with

28、 panacinar emphysema and cirrhosis.(Choice E) Pyogenic hepatic abscess typically develops as a result of local spread from infection within the biliary tree or peritoneal cavity or from hematogenous seeding of the liver. Fever, abdominal pain, chills, anorexia, weight loss, and nausea or vomiting ar

29、e common complaints, and diagnosis can be made by ultrasound or CT scan.(Choice F) Hepatic adenomas are found predominantly in young and middle-aged women who have a lengthy history of oral contraceptive usage. Hepatic adenomas are typically identified when patients complain of abdominal pain in the

30、 epigastrium or right upper quadrant, when imaging is obtained for unrelated issues, or when an individual suddenly collapses because of rupture and intraabdominal bleeding. Serum AFP levels are not elevated.Educational Objective:Individuals with stable, compensated cirrhosis who suddenly decompensa

31、te without apparent reason should be carefully evaluated for hepatocellular carcinoma, especially when serum AFP levels are also elevated.Q 24A 52-year-old Caucasian female with intense generalized pruritus is found to have high alkaline phosphatase level and high titers of antimitochondrial antibod

32、ies. Liver biopsy is performed in this patient. Morphologic findings on this patients liver biopsy are likely to resemble:A. Alcoholic hepatitis B. Acetaminophen toxicity C. Reyes syndrome D. Graft-vs-host disease E. Hemochromatosis F. Budd-Chiari syndromeA 24Correct answer:DPrimary biliary cirrhosi

33、s (PBC) is a chronic liver disease characterized by autoimmune destruction of the intrahepatic bile ducts and cholestasis.Histologically, the disease is focal and variable with a wide range in severity evident in different portions of the liver. In the precirrhotic stage, the interlobular bile ducts

34、 are destroyed by granulomatous inflammation fflorid duct lesion11) and a heavy portal tract infiltrate of macrophages, lymphocytes, plasma cells, and eosinophils is present. The similarity of these findings to those seen in graft versus host disease suggests that immunologic injury is responsible f

35、or disease manifestations.Eventually, progressive hepatic damage secondary to the obstruction in intrahepatic bile flow is observed. Upstream portal tracts undergo bile ductular proliferation, inflammation, and necrosis of adjacent parenchyma. Generalized cholestasis develops, and the liver graduall

36、y becomes grossly stained green and uniformly micronodular. Ultimately, the end-stage liver findings in PBC cannot be distinguished from those in secondary biliary cirrhosis or chronic hepatitis.(Choice A) Alcoholic hepatitis is characterized by hepatocellular swelling and necrosis, Mallory bodies,

37、neutrophilic infiltration, and fibrosis.(Choice B) Serious acetaminophen overdose is characterized by liver failure and centrilobular necrosis that can extend to include the entire lobule.(Choice C) Reye syndrome is characterized by microvesicular steatosis.(Choice E) Hemochromatosis is characterize

38、d by the deposition of hemosiderin in the liver. Cirrhosis may eventually ensue if the condition is left untreated.(Choice F) The increased intrahepatic blood pressure associated with Budd-Chiari syndrome often causes hepatomegaly, abdominal pain, and ascites secondary to thrombosis of the hepatic v

39、ein. Typically, the liver becomes grossly swollen, reddish purple, and develops a tense capsule. Severe centrilobular congestion and necrosis are observed microscopically.Educational Objective:Primary biliary cirrhosis and graft versus host disease have similar histologic findings, including granulo

40、matous bile duct destruction and a heavy lymphocyte-predominant portal tract infiltrate.Q 25A genetic abnormality of a specific protein in intestinal epithelial cells is diagnosed in an asymptomatic 20-year-old Caucasian male. The abnormality prevents expression of the protein on the basolateral sur

41、face of the intestinal cells where it normally binds to the transferrin receptor and regulates transferrin/iron complex endocytosis into the cells. This patient is at risk of developing:A.Fat malabsorption and osteoporosisB.Iron-deficiency anemiaC.Liver cirrhosis and hepatocellular carcinoma D.Basal

42、 ganglia atrophyE.Pulmonary emphysemaA 25Correct answer:CCaused by a mutation of the HFE gene on chromosome 6, hemochromatosis is an autosomal recessive disease characterized by abnormally high iron gastrointestinal absorption. The crucial site for HFE expression is the basolateral surface of epithe

43、lial cells of the small intestine crypts, where it complexes with P2-microglobulin and then binds to the transferrin receptor to regulate endocytosis of the transferrin/iron complex into cells. The iron is released once inside the cell and added to the iron regulatory pool, which determines the inte

44、nsity of apical iron uptake expression. The crypt cells in individuals with hemochromatosis have mutant HFE that is unable to detect circulating iron levels. As a result, there is unregulated expression of the iron uptake proteins and an excessive amount of iron is absorbed gastrointestinally. By mi

45、ddle adulthood, hemochromatosis causes an iron overload, primarily in parenchymal organs such as the heart, pancreas, and liver. Liver cirrhosis and hepatocellular carcinoma are two of the more ominous potential complications of this disease.(Choice A) Fat malabsorption and osteoporosis are potentia

46、l complications of chronic cholestasis.(Choice B) Iron-deficiency anemia is a potential complication of conditions such as untreated sprue or celiac syndrome.(Choice D) Basal ganglia atrophy is a potential complication of Wilsons disease.(Choice E) Pulmonary emphysema is a potential complication of

47、alpha-1 antitrypsin disease.Educational Objective:The genetic mutation of hemochromatosis prevents expression of the HFE protein on the basolateral surface of the intestinal cells where it normally binds to the transferrin receptor and regulates transferrin/iron complex endocytosis into the cells. A

48、s a result, there is unregulated expression of the iron uptake proteins and an excessive amount of iron is absorbed gastrointestinally. Liver cirrhosis and hepatocellular carcinoma are twoof the more ominous ootential comolications of this disease.Q 26A 54-year-old Caucasian male dies of profuse upp

49、er gastrointestinal hemorrhage. His liver is shown on the photograph below. This patient s condition most likely resulted from:A. Dilation of sinusoids and perivenular hemorrhages B. Substance accumulation within hepatocytesC. Intrahepatic hydatid cysts with surrounding fibrous reaction D. Fibrosis

50、and nodular parenchymal regeneration E. Granulomatous destruction of bile ducts A 26Correct answer:DThe end stage of many chronic liver diseases, cirrhosis is characterized by diffuse hepatic fibrosis with replacement of the normal lobular architecture by fibrous-lined parenchymal nodules “nodular p

51、arenchymal regeneration”). Cirrhosis is considered micronodular if most nodules are 3 mm in diameter. This patient has macronodular cirrhosis, as indicated by the multiple large cirrhotic nodules evident in the above image. His cirrhosis likely resulted in portal hypertension and the development of

52、esophageal varices, which are prone to rupture and hemorrhage.(Choice A) Dilation of sinusoids and perivenular hemorrhage is associated with acute venous outflow obstruction within the liver.(Choice B) Substance accumulation within hepatocytes occurs in conditions such as Dubin-Johnson syndrome, in

53、which the hepatocellular accumulation of coarse pigmented granules causes the liver to appear black.(Choice C) Intrahepatic hydatid cysts with surrounding fibrous reaction can be seen in patients with an Echinococcus infection.(Choice E) Granulomatous destruction of bile ducts is seen in patients wi

54、th primary biliary cirrhosis. Educational Objective:Cirrhosis is microscopically characterized by diffuse hepatic fibrosis with replacement of the normal lobular architecture by fibrous-lined parenchymal nodules.Q 27A 32-year-old IV drug abuser with several month history of fatigue and weight loss u

55、ndergoes liver biopsy. He drinks 1 ounce of alcohol daily. Light microscopy reveals hepatocytes filled with fine cytoplasmic protein granules (see the slide below). This patient most likely suffers from:A. Viral hepatitis B B. Viral hepatitis CC. Hepatic steatosisD. Primary biliary cirrhosisE. Hemoc

56、hromatosisA 27Correct answer:AThis patient suffers from chronic hepatitis B, a persistent viral infection that is one of the more common causes of hepatic injury in the United States. The acute hepatitis caused by viral infection causes several distinctive morphologic changes, including ballooning d

57、egeneration, hepatocyte necrosis, and portal inflammation. Some changes are specific to the virus. In patients infected with hepatitis B, the hepatocellular cytoplasm becomes filled with the spheres and tubules of HBsAg (the hepatitis B surface antigen) and the cytoplasm takes on a finely granular,

58、eosinophilic appearance commonly described as ground glass.(Choice B) Livers infected with hepatitis C virus commonly have lymphoid aggregates within the portal tracts and focal areas of macrovesicular steatosis.(Choice C) Hepatic steatosis is characterized by the accumulation of large and small ves

59、icles of fat within hepatocytes.(Choice D) Primary biliary cirrhosis is characterized by portal inflammation and the eventual fibrosis and destruction of the bile ducts, portal tracts, and liver parenchyma. Cirrhosis is the end stage.(Choice E) Hemochromatosis is characterized by the deposition of h

60、emosiderin in the liver Cirrhosis may eventually ensue if the condition is left untreated.Educational Objective:Hepatitis B infection causes the hepatocellular cytoplasm to fill with the spheres and tubules of HBsAg (the hepatitis B surface antigen) and take on a finely granular, eosinophilic appear