This patient's aquagenic pruritus, facial plethora, and dramatically elevated hematocrit raise strong suspicion for polycythemia vera (PV), a chronic myeloproliferative disorder marked by elevated red blood cell mass.  Although PV is often discovered incidentally on routine laboratory testing, patients may have aquagenic pruritus (itching worse with water), erythromelalgia (burning in feet/hands), transient vision disturbances (from hyperviscosity), or complications related to thrombosis/hemorrhage.  The etiology of some of these findings is unclear, but improvement in pruritus and erythromelalgia with aspirin may reflect a causative role for prostaglandins (which are pruritogenic).

Risk of venous and arterial thrombosis is significantly increased in PV due to increased blood viscosity and abnormalities in platelet and leukocyte function.  One classic thrombotic complication is Budd-Chiari syndrome, a disorder marked by hepatic venous outflow obstruction (usually due to hepatic vein thrombosis).  Manifestations may be acute, subacute, or chronic; subacute cases often present with progressive abdominal discomfort, ascites (eg, abdominal distension, flank dullness), and hepatosplenomegaly (this may also be caused by PV directly).  Mild/moderate elevations in liver transaminases, bilirubin, and alkaline phosphatase also commonly occur.

The diagnosis of Budd-Chiari syndrome is established with noninvasive imaging such as abdominal Doppler ultrasonography, which typically shows abnormal hepatic blood flow, hepatomegaly, splenomegaly, and ascites.  Patients with suspected PV (as in this case) should also undergo blood testing for the JAK2 V617F mutation, which is almost always positive.

(Choice B)  Chronic hepatitis B or C virus infection often leads to cirrhosis, which frequently causes ascites, hepatosplenomegaly, and elevated bilirubin/transaminases.  However, significant polycythemia, aquagenic pruritis, and facial plethora would be atypical.

(Choice C)  Diagnostic paracentesis can help identify spontaneous bacterial peritonitis, which usually presents with abdominal pain, fever, and hepatic encephalopathy.  Almost all cases occur in those with underlying advanced cirrhosis; polycythemia, aquagenic pruritis, and facial plethora indicate an alternate diagnosis.

(Choice D)  MR cholangiopancreatography can identify biliary tree or pancreatic head lesions.  Although biliary obstruction can cause elevated transaminases, bilirubin, and alkaline phosphatase, it would not account for the aquagenic pruritis, facial plethora, and polycythemia.

(Choice E)  Approximately 50% of patients with hepatocellular carcinoma have elevated serum alpha-fetoprotein levels.  Although hepatocellular carcinoma can present with abdominal pain, mild/moderate polycythemia (due to ectopic erythropoietin production), and decompensated cirrhosis, most cases arise in those with chronic viral hepatitis or alcohol abuse.  In addition, the presence of aquagenic pruritis, severe polycythemia (HCT > 60%), and facial plethora make PV far more likely.

(Choice F)  Ultrasound-guided liver biopsy is generally indicated when patients have cirrhosis from unclear causes or a liver lesion that cannot be diagnosed with imaging.  This patient needs abdominal imaging prior to considering a biopsy.

Educational objective:
Budd-Chiari syndrome, a condition marked by obstruction of hepatic venous outflow, often presents with subacute manifestations such as vague, progressive abdominal pain, ascites, and hepatosplenomegaly.  Polycythemia vera, a chronic myeloproliferative neoplasm associated with increased red blood cell mass, is particularly likely to cause Budd-Chiari syndrome.