Myoepithelioma is a rare benign tumor that represents less than 1 % of all salivary gland tumors. We report a case of myoepithelioma developing in the mouth floor of a 72-year-old man. The lesion was clinically suspected to be a sublingual gland tumor, and resection was performed under general anesthesia. Pathologically, the tumor was composed of plasmacytoid cells that showed positive reactions for S-100 protein, keratin, and vimentin. The tumor was diagnosed pathologically as myoepithelioma. 18 months later after the operation, the postoperative course is good, with no recurrence of the tumor.
