Localized primary amyloid tumor of the parotid gland.

We report a case of primary amyloid tumor (amyloidoma) of the left parotid gland. To the best of our knowledge this is the first case of this tumor in a parotid gland to be reported in the English literature. Congo red staining with prior potassium permanganate incubation confirmed the localized primary type of amyloid. Immunocytochemical studies demonstrated staining for immunoglobulin A, lambda and kappa light chains within the amyloid deposits and in the cytoplasm of the lymphocytes, and plasma cell aggregates. Ultrastructural examination showed characteristic findings of straight, nonbranching fibrils, measuring 80 to 100 A in length, that were diagnostic of amyloid. The patient had no symptoms and no clinical or laboratory evidence of systemic amyloidosis or multiple myeloma at a 1-year follow-up examination.