Salivary duct carcinoma in the mandible: report of a case with immunohistochemical studies.

Salivary duct carcinoma is rare. We describe a 56-year-old man who developed salivary duct carcinoma in the mandible 10 years after removal of the right second and third molars. The tumour originated in the retromolar gland or the ectopic minor salivary gland in the mandible. The panoramic radiograph showed a radiolucent, poorly circumscribed area about 40 x 30 mm in size and distal to the lower right first molar. This tooth, together with all neoplastic tissue, was removed, and histopathological examination showed it to be a salivary duct carcinoma in the mandible. On immunohistochemical staining, keratin antibodies stained the ductal structure, 1A4 antibody stained myoepithelial cells, but S-100 protein and vimentin were not seen. The patient was well and with no sign with recurrence 6 years postoperatively.