A Case of IgG4-related Sclerosing Disease with Salivary Duct Carcinoma

IgG4-related sclerosing disease, including Mikulicz’s disease, is systemic, with IgG4-positive plasma cells appearing in internal organs body-wide. Sclerosing salivary glanditis such as Mikulicz’s disease and Kuttner’s tumor, autoimmune pancreatitis, primary sclerosing cholangitis, and retroperitoneal fibrosis are assumed to be phenotypes of IgG4-related sclerosing disease. Some cases of autoimmune pancreatitis complicated by malignant tumor have been reported, but few in the head and neck field. We detail a case of IgG4-related sclerosing disease complicated by salivary duct carcinoma.