Primary localization amyloidosis of the sublingual gland.

: We here in present a very rare case of primary localized amyloidosis with amyloid A protein of the sublingual gland. It presented a tumorous appearance on the left oral floor. Pretreatment with potassium premanganate made biopsy specimens unstained by Congo red. Immunohistochemical staining for AA protein was positive. Systemic amyloidosis was ruled out based on clinical and laboratory examinations. The gastric and the labial salivary glands biopsy showed no amyloid deposits. As far as we know, this is the first case of primary localized amyloidosis with amyloid A protein of the oral cavity, and tumor-formed amyloidosis of the sublingual gland.