Immunoglobulin G4-related Disease: Presentation of the First Case with Isolated Pterygopalatine Fossa Involvement

Immunoglobulin G4-related disease is an immune-mediated fibroinflammatory disease with single or multiple organ involvement. Clinically it mimics several benign and malignant tumors, as well as infectious, and inflammatory disorders. It typically presents as multiple tumor-forming lesions. Histological and immunohistochemical findings are characteristic. Serum immunoglobulin G4 levels are usually increased. Systemic corticosteroid administration is the treatment of choice with good response, especially in early disease stages. We present the first case of immunoglobulin G4-related disease presenting as an isolated tumor forming lesion of the left pterygopalatine fossa. Imaging studies indicated a benign process. Histological findings were consistent with IgG4-related disease. The patient showed a good response to systemic corticosteroid treatment and remains free of symptoms 18 months following diagnosis.