hepatic adenoma

Hepatic adenoma is a benign monoclonal proliferation of hepatocytes arising in an otherwise normal liver, most commonly in women aged 20-44 with a strong association with long-term oral contraceptive pill (OCP) use (estrogen-dependent growth) and anabolic androgenic steroid use in men/bodybuilders. Other associations include glycogen storage disease type I (von Gierke disease) and pregnancy, which can promote tumor growth. Molecular subtypes include HNF1A-inactivated, inflammatory (associated with obesity/metabolic syndrome, elevated CRP/SAA), and beta-catenin-activated (higher malignant potential, associated with male sex and androgen use). Clinically, many adenomas are asymptomatic and discovered incidentally on imaging, but they can present with right upper quadrant pain due to hemorrhage or, rarely, rupture causing hemoperitoneum and hypotension—a surgical emergency. Diagnosis is typically via contrast-enhanced MRI or CT showing arterial enhancement with washout; biopsy is sometimes needed but carries bleeding risk. Management includes discontinuation of OCPs/steroids, which may cause regression, and surveillance imaging. Surgical resection is recommended for lesions >5 cm, beta-catenin-activated subtype, symptomatic lesions, or those in men (due to higher malignant transformation risk) because of concern for hemorrhage and rare progression to hepatocellular carcinoma. This entity is frequently tested in relation to distinguishing benign liver lesions (hepatic adenoma vs. focal nodular hyperplasia vs. hepatocellular carcinoma) based on risk factors, imaging, and histology.