免疫球蛋白G4 相關性膽管炎(IgG4-associated cholangitis) 在臨床病理上是一個新興的疾病。先前認為它是屬於自體免疫性胰臟炎(autoimmune pancreatitis) 的胰臟外合併症之一。目前則將它重新歸類為免疫球蛋白G4 相關性硬化疾病(IgG4-associated sclerosing disease) 之一。這類疾病的特點是血清中有高濃度的免疫球蛋白G4 與被侵犯的器官中有廣泛的帶免疫球蛋白G4 之漿細胞的浸潤。我們報告一個臨床上酷似膽管癌的阻塞性黃疸患者，於手術後證實為免疫球蛋白G4 相關性膽管炎的病例。

Immunoglobulin G4 (IgG4)-associated cholangitis is a novel clinicopathological disease entity. It was formerly recognized as one of extrapancreatic diseases of autoimmune pancreatitis. Now, it is redesignated as one of the IgG4- associated sclerosing diseases, which are characterized by high serum IgG4 concentrations and extensive infiltration of IgG4-positive plasma cells into the involved organs. We described a case of obstructive jaundice had a clinical presentation resembling cholangiocarcinoma proved to be IgG4-associated cholangitis after surgery.