Ig-G4 RELATED DISEASE: A CASE REPORT

Abstract

IgG4-related disease (IgG4-RD) is an inflammatory condition that exhibits diffuse or local organ swelling and hypertrophic changes with elevated serum IgG4 levels and infiltration of IgG4-positive plasma cells in multiple organs. The patient was a 72-year-old Japanese man, in whom magnetic resonance imaging (MRI) revealed retroperitoneal fibrosis with elevated serum IgG4 levels. He was referred to our department for a possible salivary gland biopsy to avoid invasive examination in the retroperitoneal region. Examinations with computed tomography and MRI failed to detect significant abnormalities in the salivary glands. Labial salivary gland biopsy was then performed under local anesthesia and resulted in diagnosis of IgG4-RD with typical histopathological findings (marked lymphoplasmacytic infiltration, fibrosis, and infiltration of IgG4-positive cells: IgG4⁺/IgG⁺ >40% and >10 IgG4⁺ plasma cells/HPF). This case suggests that labial salivary gland biopsy is useful as a low-invasive method for diagnosis of IgG4-RD, although a biopsy targeting the site of origin is ideal.