Immunoglobulin G4-associated cholangitis mimicking cholangiocarcinoma in a young boy.

Autoimmune pancreatitis is a rare form of chronic pancreatitis, which commonly mimics pancreatic carcinoma. Immunoglobulin G4-associated cholangitis (IAC) is a rare type of autoimmune pancreatitis associated with bile duct involvement, which can present with or without pancreatic involvement. Usually, the bile duct involvement is in the form of multiple intra-and extra-hepatic strictures mimicking primary sclerosing cholangitis. Rarely, there can be an isolated stricture which mimics cholangiocarcinoma. Differentiating these from cholangiocarcinoma, though extremely difficult, is of critical importance since it can be treated without surgical intervention. Most cases with rare presentation mimicking cholangiocarcinoma have been reported in elderly patients. We present one such rare presentation of autoimmune pancreatitis in a young 13-year-old patient in whom hepaticojejunostomy was done for a hilar stricture, which later turned out to be related to IAC. To our knowledge this is the first reported case of its kind from India.