IgG4 Related Sclerosing Cholangitis

IgG4 related disease (IgG4-RD) is a multisystemic disorder which has only recently been recognized. IgG4 related sclerosing cholangitis (IgG4-SC) is the biliary manifestation of the disease, often in association with autoimmune pancreatitis (AIP). In this review, we provide an overview of IgG4-RD, with a focus on the biliary manifestations. In particular, we describe the important differential diagnoses of IgG4-SC that need to be considered, namely, primary sclerosing cholangitis (PSC) and cholangiocarcinoma, and provide a management algorithm. Finally, we highlight future directions and unanswered questions which will provide new insights into this exciting and evolving disease entity.