A 31-year-old woman has a 4 cm liver lesion found incidentally. MRI shows a central scar with radiating septa. Biopsy shows benign-appearing hepatocytes arranged in plates one to two cells thick, separated by fibrous bands containing proliferating bile ductules and abnormal thick-walled vessels. Immunostaining shows map-like glutamine synthetase positivity. The diagnosis is:
- A Hepatocellular adenoma, inflammatory subtype
- B Fibrolamellar hepatocellular carcinoma
- C Focal nodular hyperplasia ✓
- D Hepatocellular carcinoma, well differentiated
Explanation
Focal nodular hyperplasia is a hyperplastic response to a preexisting arterial malformation, occurring mainly in young women. It features a central stellate scar with fibrous bands containing ductular reaction and aberrant vessels, and the surrounding hepatocytes show characteristic map-like glutamine synthetase staining due to disorganized zones 3-like differentiation. Fibrolamellar carcinoma occurs in adolescents without cirrhosis and shows malignant cytology with lamellar fibrosis and often a DNAJB1-PRKACA fusion. Adenomas lack bile ducts and scars, and well-differentiated HCV-related HCC arises in cirrhotic liver.
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.