Autoimmune cholangiopathy presenting as a mimicker of hilar cholangiocarcinoma.

BACKGROUND AND AIMS: Autoimmune cholangiopathy can mimic cholangiocarcinoma. This video highlights the presentation and management of a patient with obstructive jaundice in the setting of a biliary stricture concerning for hilar cholangiocarcinoma who had resolution of her symptoms with steroids. METHODS: A 49-year-old woman without autoimmune history presented with abdominal pain and jaundice and was found to have elevated liver enzymes (total bilirubin, 4.7 mg/dL; alkaline phosphatase, 405 U/L; aspartate aminotransferase, 174 U/L; and alanine aminotransferase, 530 U/L), a mass at the hepatic duct confluence, and a filling defect in the common bile duct on cross-sectional imaging. Serum carbohydrate antigen 19-9 (9 U/mL) and immunoglobulin G4 (IgG4)/IgG (7.2%) were normal. After multiple negative samples obtained by EUS/ERCP, including brushing, biopsy, and fluorescence in situ hybridization, she opted to trial systemic steroids for suspected autoimmune cholangiopathy. RESULTS: After 4 weeks of prednisone, an EUS/ERCP was performed and noted improvement in biliary duct dilatation, duct wall thickness, and stricture size. The periductal mass was not appreciated. Repeat cholangioscopy noted gross improvement in duct stenosis and neovascular changes. At 4-month follow-up, she remained clinically asymptomatic, with normal laboratory values and no radiographic evidence of a hilar mass or bile duct stricture. CONCLUSIONS: Autoimmune cholangiopathy can mimic cholangiocarcinoma and should be considered when the cytopathology result of hilar strictures is repeatedly negative.