What smells
A 48-year-old woman presents to the emergency department with severe right upper quadrant abdominal pain, fever, and progressive confusion. Three days ago she was discharged following hospitalization for gallstone pancreatitis, during which she underwent ERCP with stone extraction. Her husband reports that she initially improved but then developed worsening jaundice, dark urine, generalized itching, and shaking chills. On examination she is febrile to 39.5°C (103.1°F), blood pressure is 86/54 mmHg, heart rate is 124/min, and she isoriented only to person. Laboratory studies show leukocytosis with bandemia, elevated alkaline phosphatase, direct hyperbilirubinemia,and elevated lactate.
Which of the following mechanisms BEST explains why biliary obstruction predisposes patients to the most likely diagnosis?
A. Decreased pancreatic bicarbonate secretion allows bacterial proliferation
B. Loss of bile-mediated flushing and antimicrobial defenses permits ascending infection
C. Increased bilirubin production causes toxic injury to biliary epithelium
D. Activation of Kupffer cells leads directly to bacterial translocation
E. Reduced hepatic gluconeogenesis promotes bacterial growth in bile
B. Loss of bile-mediated flushing and antimicrobial defenses permits ascending infection
A 49-year-old woman presents with jaundice, dark urine, pale stools, and intense generalized pruritus due to obstruction of the commonbile duct by a gallstone. She asks why she has been scratching constantly despite having no skin rash. Physical examination showsnumerous excoriations on her arms and chest.
Which of the following is the most likely explanation for her pruritus?
A. Histamine release from mast cells in the dermis
B. Deposition of bilirubin crystals within the epidermis
C. Reflux of bile acids and other pruritogens into the systemic circulation
D. Immune complex deposition within cutaneous blood vessels
E. Direct bacterial invasion of the skin
C. Reflux of bile acids and other pruritogens into the systemic circulation
A 52-year-old woman presents with progressive jaundice, dark urine, severe pruritus, and pale-colored stools. Imaging demonstrates anobstructing stone within the common bile duct. Laboratory studies reveal markedly elevated alkaline phosphatase and direct bilirubin.
Which substance is most directly responsible for the normal brown coloration of stool that is absent in this patient?
A. Biliverdin
B. Conjugated bilirubin
C. Stercobilin
D. Urobilin
E. Porphobilinogen
C. Stercobilin
A patient with recurrent choledocholithiasis presents with jaundice and laboratory studies showing an INR of 1.8 and PT of 17 seconds.Platelet count is normal. The physician explains that obstruction of bile flow is contributing to her abnormal coagulation studies.
Deficiency of which clotting factors is most directly responsible for her laboratory abnormalities?
A. I, II, V, VIII
B. II, VII, IX, X
C. II, VIII, X, XI
D. VII, VIII, IX, XII
E. V, VII, X, XIII
B. II, VII, IX, X
A 54-year-old construction supervisor reports fatigue and intermittent right upper quadrant discomfort. He acknowledges drinking six toeight beers daily for many years. He has obesity, type 2 diabetes mellitus, and hypertension. Physical examination reveals mildhepatomegaly.
Laboratory studies:
Hepatitis serologies are negative.
Which of the following BEST explains the observed AST predominance?
A. Alcohol selectively increases AST gene transcription
B. Alcohol causes pyridoxal phosphate deficiency and mitochondrial injury
C. AST is produced by activated hepatic stellate cells
D. ALT is preferentially excreted into bile
E. Alcohol increases Kupffer cell release of AST
B. Alcohol causes pyridoxal phosphate deficiency and mitochondrial injury
A liver biopsy from a patient with alcohol-associated steatohepatitis demonstrates eosinophilic cytoplasmic inclusions within balloonedhepatocytes. These inclusions stain positively for ubiquitinated cytokeratin intermediate filaments.
Which of the following best describes these structures?
A. Councilman bodies
B. Mallory-Denk bodies
C. Russell bodies
D. Psammoma bodies
E. Schaumann bodies
B. Mallory-Denk bodies
A liver biopsy is performed on a patient with chronic alcohol use and steatohepatitis. Histology demonstrates macrovesicular steatosis,hepatocyte ballooning degeneration, Mallory-Denk bodies, and pericellular ("chicken-wire") fibrosis surrounding hepatocytes.
Which of the following cell types is primarily responsible for producing the extracellular matrix deposited in this patient's liver?
A. Cholangiocytes
B. Kupffer cells
C. Hepatic stellate cells
D. Sinusoidal endothelial cells
E. Regenerating hepatocytes
B. Kupffer cells
A patient is admitted to the ICU after septic shock from ascending cholangitis. Her blood pressure is 82/46 mmHg. Serum lactate iselevated.
The elevated lactate is most directly caused by which of the following?
A. Increased aerobic metabolism within hepatocytes
B. Excess bilirubin production by macrophages
C. Increased anaerobic glycolysis due to tissue hypoperfusion
D. Reduced conversion of lactate into pyruvate
E. Hepatic glycogen depletion
C. Increased anaerobic glycolysis due to tissue hypoperfusion
A patient with complete obstruction of the common bile duct develops jaundice and tea-colored urine. Laboratory studies demonstrateelevated direct bilirubin.
Why is the urine dark?
A. Excess unconjugated bilirubin is filtered by the kidneys
B. Biliverdin is excreted in urine
C. Water-soluble conjugated bilirubin is filtered into urine
D. Urobilinogen accumulation causes urine discoloration
E. Hemolysis releases free heme into urine
C. Water-soluble conjugated bilirubin is filtered into urine
A patient with chronic alcohol use undergoes liver biopsy demonstrating centrilobular steatosis and fibrosis.
Which of the following best explains why zone 3 hepatocytes are injured first?
A. Zone 3 receives the highest oxygen concentration
B. Zone 3 contains the highest concentration of Kupffer cells
C. Zone 3 receives blood directly from the portal vein
D. Zone 3 has the lowest oxygen tension and highest CYP2E1 activity
E. Zone 3 produces most hepatic albumin
D. Zone 3 has the lowest oxygen tension and highest CYP2E1 activity
A 59-year-old man with decompensated cirrhosis is brought to the hospital because of progressive confusion. His daughter reports that hehas become forgetful, sleeps during the day, and remains awake at night. Physical examination demonstrates asterixis. Serum ammoniaconcentration is increased.
Within the central nervous system, excess ammonia is primarily detoxified by conversion of glutamate into which of the followingcompounds?
A. Carbamoyl phosphate
B. Citrulline
C. GABA
D. Glutamine
E. Ornithine
D. Glutamine
Blood cultures from a patient with severe ascending cholangitis grow:
Which organism is most likely?
A. Streptococcus pyogenes
B. Staphylococcus aureus
C. Enterococcus faecalis
D. Streptococcus pneumoniae
E. Listeria monocytogenes
C. Enterococcus faecalis
A 61-year-old man with alcohol-associated cirrhosis and portal hypertension presents with unintentional weight loss and worsening fatigue. Serum alpha-fetoprotein concentration is 420 ng/mL. MRI reveals a solitary 3.5-cm arterial-enhancing hepatic lesion with delayed venouswashout. The lesion is categorized as LI-RADS 5.
Which of the following molecular abnormalities is most commonly associated with the development of this patient's malignancy?
A. APC mutation
B. KRAS activation
C. RET rearrangement
D. TERT promoter mutation
E. BRCA1 loss-of-function mutation
D. TERT promoter mutation
A 63-year-old man with long-standing alcohol-associated cirrhosis undergoes routine surveillance imaging. MRI reveals a 4-cm arterial-enhancing lesion with delayed washout. AFP is markedly elevated. No biopsy is obtained.
Which of the following imaging findings most strongly supports the diagnosis of hepatocellular carcinoma?
A. Dense central calcification
B. Peripheral rim enhancement
C. Arterial enhancement with venous washout
D. Homogeneous enhancement throughout all phases
E. Multiple cystic spaces
C. Arterial enhancement with venous washout