A 40-year-old man with ulcerative colitis presents with progressive fatigue and jaundice. ALP is markedly elevated. MRCP shows multifocal strictures and dilations of intrahepatic and extrahepatic bile ducts ('beaded' appearance). Liver biopsy shows periductal 'onion skin' fibrosis. The diagnosis is:

• A Primary biliary cholangitis (PBC)
• B Autoimmune hepatitis
• C Secondary sclerosing cholangitis
• D Primary sclerosing cholangitis (PSC) ✓

Explanation

PSC is strongly associated with ulcerative colitis (~75% of PSC patients have IBD), presents with progressive cholestasis, and MRCP characteristically shows multifocal strictures and dilations creating the 'beaded' duct pattern. Liver biopsy shows the pathognomonic periductal concentric 'onion skin' fibrosis around bile ducts. PBC affects small bile ducts with florid duct lesions (granulomatous cholangitis), positive AMA antibodies, and is associated with other autoimmune conditions but not UC. Autoimmune hepatitis shows interface hepatitis with plasma cell infiltrates.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.