Can a liver ultrasound be normal in a patient with polycythemia vera (PV)?

Can a Liver Ultrasound Be Normal in Polycythemia Vera?

Yes, a liver ultrasound can be completely normal in polycythemia vera, particularly in early disease or when vascular complications have not yet developed. 1

Understanding the Relationship Between PV and Liver Imaging

Polycythemia vera does not inherently cause structural liver abnormalities that would be visible on ultrasound. The liver parenchyma itself is typically normal unless complications develop. 1 The key ultrasound findings in PV are related to vascular complications, not primary liver disease.

When Ultrasound Findings Are Normal

A normal liver ultrasound in PV occurs when:

• No thrombotic complications have developed - The hepatic veins, portal vein, and inferior vena cava remain patent without thrombosis 1
• Portal hypertension has not yet occurred - No splenomegaly, no portosystemic collaterals, and normal portal vein diameter 1
• Early disease stage - Before the hyperviscosity and thrombotic tendency have caused vascular events 2, 3

Critical Vascular Complications to Assess

When performing ultrasound in PV patients, the focus should be on detecting:

Budd-Chiari Syndrome

• PV accounts for approximately 49% of all Budd-Chiari syndrome cases, making this the most important complication to exclude 1, 4
• Doppler ultrasound should specifically assess hepatic vein patency, as it has diagnostic sensitivity >75% for Budd-Chiari syndrome 1, 4
• Non-visualization of hepatic veins is the hallmark finding, though ultrasound can have false positive/indeterminate results in approximately 50% of cases 4, 5
• Large intrahepatic or subcapsular collateral vessels are present in >80% of Budd-Chiari cases 1, 4

Portal Hypertension Features

• Portosystemic collaterals on ultrasound are 100% specific for clinically significant portal hypertension and should be actively searched for 6, 1
• Splenomegaly should be measured and documented, as it contributes to risk stratification 6, 1
• Portal vein thrombosis with cavernous transformation can occur in PV patients with non-cirrhotic portal hypertension 7

Clinical Context Matters

The absence of ultrasound abnormalities does not exclude PV - the diagnosis is based on hematologic criteria (elevated red cell mass, JAK2V617F mutation in >95% of cases, bone marrow findings), not imaging 3, 8

Conversely, unusual thrombosis patterns in patients under 55 years without chronic liver disease should prompt evaluation for PV, even when other findings are subtle 1

Important Clinical Pitfalls

• Do not assume liver disease is present based solely on a PV diagnosis - the liver ultrasound may remain normal throughout the disease course if vascular complications do not develop 1
• Splenomegaly in PV has multiple causes - it can result from extramedullary hematopoiesis (part of the myeloproliferative process itself) or from portal hypertension secondary to thrombotic complications 2, 7
• Four out of five patients in one case series had moderate-to-severe esophageal varices despite relatively preserved liver function (Child A-B), indicating that portal hypertension can develop without cirrhosis in PV 7
• If thrombotic complications are suspected but ultrasound is equivocal, MRI or direct venography should be pursued rather than assuming the ultrasound excludes pathology 4

Surveillance Recommendations

In PV patients with normal baseline ultrasound:

• Esophagogastroduodenoscopy should be performed early and regularly if any signs of portal hypertension develop, as primary prevention of variceal hemorrhage is critical 7
• Serial ultrasound monitoring may be warranted in patients with additional thrombotic risk factors (age >60 years, prior thrombosis, poorly controlled blood counts) 3, 7
• Doppler assessment of hepatic veins should be included in any abdominal ultrasound performed on PV patients to screen for early Budd-Chiari syndrome 1, 4