Parotid clear-cell adenoma of possible myoepithelial origin

A case of a parotid tumor occurring in a 67-year-old man, who had noted a slowly gowing swelling under the left ear 4 years prior to admission to the hospital, is described. At operation, the tumor was pale and firm, encapsulated, and did not affect the facial nerve. Histologically, it consisted of polyhedral cells with clear cytoplasm and regular nuclei surrounding remnants of the acinar secretory system of the gland. Histologically and electron microscopically, the picture was compatible with the diagnosis of myoepithelial clear-cell adenoma. The tumor is considered to be a rare variant of the pleomorphic adenoma but with sufficiently characteristic features to be separated as a diagnostic entity. At follow-up 22 months after resection of the superficial lobe containing the tumor, the patient is symptom free.