IgG4-related disease: case report and literature review.

IgG4-related disease (IgG4-RD) is relatively a new growing entity of immune-mediated origin, characterized by a mass-forming lesion, the infiltration of IgG4-positive plasma cells and occasionally elevated serum IgG4. It is considered to be both a systemic inflammation and sclerosing disease. The most common manifestations are parotid and lacrimal swelling, lymphadenopathy and autoimmune pancreatitis. Sclerosing cholangitis and retroperitoneal fibrosis are among the other mentioned frequent manifestations. The diagnosis should be approved histo-pathologically but other conditions such as lymphoma should be carefully excluded. Patients with IgG4-RD respond beneficially to glucocorticoid therapy especially when given at early onset stages. In some cases, the combination of immunosuppressive agents is required.