A Case of IgG4-Related Sclerosing Disease With Retroperitoneal Fibrosis, Autoimmune Pancreatitis and Bilateral Focal Nephritis

A 74-year-old male patient presented with progressive anorexia, cholestatic liver function tests, and a diffuse enlarged pancreas suggestive of a pancreatic carcinoma. There was a marked elevation of total immunoglobulin G4 (IgG4) in serum. Further investigation led to the diagnosis of IgG4-related sclerosing disease with involvement of the pancreas, retroperitoneal fibrosis, and bilateral focal nephritis. To our knowledge, this is the first report on these 3 clinical entities occurring in the same patient. A short review of the literature concerning autoimmune pancreatitis and retroperitoneal fibrosis is made, with special interest to the concept of IgG4-related pathology. This systemic disease can have several clinical manifestations: IgG4-positivity not only can be found in the pancreas, but also at the level of extrahepatic biliary ducts, gallbladder, salivary glands, retroperitoneal tissue, kidneys, ureters, and lymph nodes. Although further investigation is required to determine its exact pathophysiologic role, IgG4 seems to be an important key player.