ABSTRACT
IgG4-associated cholangitis [IAC] is a subgroup of IgG4-related disease, which is more common in elderly men. IAC is frequently coincident with autoimmune pancreatitis [AIP]. However, some IAC cases do not have other organs involvement. The diagnosis of IAC is based on biochemical, radiological, and histological features. Among these, elevated serum levels of IgG4, extra- and intrahepatic biliary strictures [as visualized by cholangiography], lymphoplasmacytic infiltrations in the liver and bile duct tissue, and association with AIP are of key importance. IAC may mimic primary sclerosing cholangitis or cholangiocarcinoma [CC]. It is classically a corticosteroid-responsive condition and corticosteroid is regarded as the initial treatment of choice in this disease. However, relapse following corticosteroid withdrawal is a frequent event