A 29-year-old woman on oral contraceptives presents with sudden right upper quadrant pain, rapidly accumulating ascites, and tender hepatomegaly. Doppler ultrasound shows absent flow in all three hepatic veins. Contrast CT reveals marked hypertrophy of one hepatic segment with relative sparing of the rest. Which segment is characteristically enlarged, and what haematologic test should follow?

• A Caudate lobe; test for JAK2 V617F mutation ✓
• B Segment IV; test for antiphospholipid antibodies only
• C Left lateral segment; test for factor V Leiden
• D Right posterior segment; test for protein C deficiency only

Explanation

In Budd-Chiari syndrome the caudate lobe enlarges because its venous drainage enters the inferior vena cava directly through separate short veins, allowing compensatory hypertrophy when the main hepatic veins thrombose. Myeloproliferative neoplasms are the commonest cause, so screening for the JAK2 V617F mutation is mandatory even with normal blood counts. Oestrogen-containing contraceptives are an recognised trigger here.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.