Clinical scenario: tense ascites | tender hepatomegaly | absent flow in hepatic vein
A 14-year-old boy presents with a 3-week history of progressive abdominal distension, right upper quadrant pain, and bilateral leg swelling. He has no history of chronic liver disease, blood transfusions, or jaundice. On examination, he has tense ascites, tender hepatomegaly (liver span 16 cm), and dilated abdominal wall veins. There is no splenomegaly. Laboratory investigations reveal mildly elevated AST and ALT, serum bilirubin 1.8 mg/dL, serum albumin 3.5 g/dL, and INR 1.6. Ascitic fluid analysis shows a SAAG of 1.6 g/dL with low protein-cell count. Doppler ultrasonography demonstrates non-visualization of the hepatic veins with absent venous flow, while the portal vein is patent.
What is the most likely diagnosis?
A. Budd–Chiari syndrome
B. Constrictive pericarditis
C. Portal vein thrombosis
D. Sinusoidal obstruction syndrome (veno-occlusive disease)
E. Wilson disease
Correct answer & Explanation:
Correct answer: A. Budd–Chiari syndrome
Explanation
The patient has the classic features of Budd–Chiari syndrome, which is caused by hepatic venous outflow obstruction. The hallmark clinical triad includes:
- Right upper quadrant pain
- Tender hepatomegaly
- Ascites
The high SAAG ascites indicates portal hypertension. The diagnostic clue is the absence of flow in the hepatic veins on Doppler ultrasonography, which is the first-line imaging modality and is highly sensitive for hepatic vein thrombosis or obstruction.
Why the other options are incorrect
B. Constrictive pericarditis
- Can cause hepatomegaly and ascites due to systemic venous congestion, but Doppler would show patent hepatic veins, and echocardiography would demonstrate pericardial disease.
C. Portal vein thrombosis
- Causes portal hypertension and splenomegaly, but hepatic venous flow remains normal. Doppler would show thrombosis of the portal vein, not the hepatic veins.
D. Sinusoidal obstruction syndrome (veno-occlusive disease)
- Typically occurs after hematopoietic stem-cell transplantation or high-dose chemotherapy, presenting with painful hepatomegaly, jaundice, and weight gain. Hepatic veins are usually patent on Doppler.
E. Wilson disease
- Causes chronic liver disease, acute liver failure, or neurological manifestations, but does not produce hepatic vein occlusion on imaging.
High-yield pearl
In any child or adolescent with the combination of painful hepatomegaly, high-SAAG ascites, and absent hepatic venous flow on Doppler, the diagnosis is Budd–Chiari syndrome until proven otherwise. After diagnosis, the next step is to investigate for an underlying prothrombotic disorder (e.g., protein C deficiency, protein S deficiency, antithrombin III deficiency, or Factor V Leiden).
