A 29-year-old woman on combined oral contraceptive pills presents with sudden right upper quadrant pain and hypotension. CT shows a 6 cm heterogeneous right lobe liver mass with intraperitoneal haemorrhage. Resection histology shows a benign proliferation of hepatocytes without portal tracts or bile ducts. Which molecular subtype of this tumour carries the highest risk of malignant transformation?

• A HNF1A-inactivated subtype
• B Beta-catenin activated subtype ✓
• C Inflammatory (IL6/JAK-STAT) subtype
• D Unclassified subtype

Explanation

The lesion is a hepatocellular adenoma complicated by haemorrhage, a known event in large adenomas in women on oestrogens. Among the molecular subtypes, beta-catenin activated adenomas have the highest rate of transformation to hepatocellular carcinoma and require resection even when small. HNF1A-inactivated adenomas are multiple and steatotic but low risk, while inflammatory adenomas carry mainly a bleeding risk related to sinusoidal dilatation.

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.