A Case of Myoepithelioma of the Soft Palate

Abstract

Myoepithelioma is a relatively rare salivary gland tumor. Herein, we report a case of myoepithelioma of the soft palate. The patient was 48-year-old man who was found, during dental examination, to have a swelling on the left side of the soft palate, and was referred to a local clinic. Fine-needle aspiration cytology revealed ductal epithelial cells and myoepithelial cells, so that the initial diagnosis was pleomorphic adenoma. The patient was referred to our department, and we performed resection of the soft palate tumor. On histopathological examination, the tumor was found to be composed of plasmacytoid myoepithelial cells, and immunohistochemistry showed positive staining of the cells for AE1/AE3, S-100 protein, vimentin, and GEAP. The MIB-1 index, an indicator of malignant cell proliferation, was low (4%). The final diagnosis of the tumor was myoepithelioma, plasmacytoid cell type. Until the last follow-up, one year after the surgery, the patient showed no evidence of recurrence. Because several reports have suggested that myoepitheliomas could show malignant transformation, we propose to carefully follow-up our patient reported herein, with oral myoepithelioma.