IgG4-related submandibular gland disease

Definition

A rare IgG4-related disease characterized by a benign tumor-like chronic inflammatory lesion of the submandibular gland. Histologic features are periductal fibrosis, acinar atrophy, obliterative phlebitis, dense lymphoplasmacytic infiltrates rich in IgG4-positive plasma cells, and formation of lymphoid follicles. Lobular architecture is preserved. Patients most commonly present with unilateral, painless swelling of the submandibular gland. Serologic analysis reveals elevated IgG4 levels.