A 45-year-old woman with primary sclerosing cholangitis (PSC) undergoes liver biopsy. The pathognomonic histological finding in PSC is:

• A Florid duct lesion with lymphoplasmacytic infiltrate and granulomas around bile ducts
• B Periductal concentric fibrosis ('onion-skin' fibrosis) around medium and large bile ducts ✓
• C Plasma cell-rich portal infiltrate with rosette formation and interface hepatitis
• D Ductopenia (loss of bile ducts in >50% of portal tracts) with copper deposition

Explanation

PSC is characterized histologically by periductal concentric fibrosis — lamellar 'onion-skin' fibrosis surrounding medium and large interlobular and septal bile ducts, eventually leading to duct obliteration and replacement by fibrous cords. This pattern is pathognomonic of PSC when present, although early PSC biopsies may show only nonspecific portal inflammation. The florid duct lesion (granulomatous bile duct destruction) with lymphoplasmacytic infiltrate is characteristic of primary biliary cholangitis (PBC). Plasma cell-rich interface hepatitis with rosette formation is autoimmune hepatitis. Ductopenia with copper accumulation represents end-stage ductopenic disease or advanced PBC.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.