A 2-Week Steroid Trial for Differentiating Isolated IgG4-Related Sclerosing Cholangitis from Cholangiocarcinoma

Immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) is rare disease which is steroid-responsive and often associated with IgG4 related systemic disease such as autoimmune pancreatitis. It is characterized by increased serum IgG4 and IgG4- positive lymphoplasmacytic infiltration in bile ducts. It is often difficult to distinguish IgG4-SC to hilar cholangiocarcinoma if it manifests as an isolated bile duct. We report a case of 79-year-old woman with IgG4-SC which was difficult to distinguish hilar cholangiocarcinoma due to similar clinical and radiologic findings, showing good therapeutic effect after a 2-week steroid trial.