If you’re preparing for the United States Medical Licensing Examination® (USMLE®) Step 2 exam, you might want to know which questions are most often missed by test-prep takers. Check out this example from Kaplan Medical, and read an expert explanation of the answer. Also check out all posts in this series.
This month’s stumper
Over a two-month period, a 50-year-old woman with a history of polycythemia vera develops abdominal pain and gross ascites. Physical examination demonstrates smooth hepatomegaly and mild jaundice. Pressure applied over the liver fails to distend the jugular veins. The abdomen is grossly edematous and the abdominal wall shows a tortuous venous pattern. Edema of the legs is prominent.
Which of the following is the most likely diagnosis?
A. Budd-Chiari syndrome.
B. Hepatic cirrhosis.
C. Hepatocellular carcinoma.
D. Primary sclerosing cholangitis.
E. Hepatic steatosis.
The correct answer is A.
Kaplan Medical explains why
Budd-Chiari syndrome is a disorder in which hepatic venous outflow is obstructed because of thrombosis of the major hepatic veins. The blood clots may extend into the inferior vena cava, causing the abdominal wall signs and edema of the legs illustrated in the question stem.
The condition is rare and typically occurs in the setting of a coagulopathy due to hematologic disease (myeloproliferative disorders, polycythemia vera, sickle cell disease, paroxysmal nocturnal hemoglobinuria) or in disorders of the coagulation (defects in normal inhibitors, such as antithrombin III, protein C, protein S, factor V Leiden; antiphospholipid antibodies; and possibly high estrogen states, such as oral contraceptive use or pregnancy). The disorder either presents with acute hepatic failure or, more commonly, progresses over several months.
Early recognition of the syndrome is important so that thrombolytics and long-term anticoagulation can be given. Some patients respond to medical management, whereas others with fulminant or end-stage disease may require liver transplantation.
Why the other answers are wrong
Choice B: Hepatic cirrhosis develops slowly and produces a nodular liver. Hepatic vein thrombosis is not associated.
Choice C: Hepatocellular carcinoma would produce a liver mass. Ascites is a late finding and usually develops slowly. Portal vein, rather than hepatic vein, thrombosis may occur.
Choice D: Primary sclerosing cholangitis is an inflammation of the bile ducts that does not usually produce ascites unless it has progressed to cirrhosis.
Choice E: Hepatic steatosis, or fatty liver, does not produce ascites.
For more prep questions on USMLE Steps 1, 2 and 3, view other posts in this series.
The AMA and Kaplan have teamed up to support you in reaching your goal of passing the USMLE® or COMLEX-USA®. If you're looking for additional resources, Kaplan provides free access to tools for pre-clinical studies, including Kaplan’s Lecture Notes series, Integrated Vignettes, Shelf Prep and more.
