A 51-year-old man with parotid gland tumor that showed a tendency to rapid exacerbation 20 years after the subjective recognition of the mass is reported with reference to the literature.The tumor parenchyma from this patient showed poorly differentiated mucoepidermoid tumors. From the widespread hyalinization and relatively;filmdom elastic fibers in the stroma, and the clinical course, it was highly possible that the patient had carcinoma in pleomorphic adenoma.The patient was treated by external irradiation and chemotherapy (5-FU, PEP), after total parotidectomy and total neck dissection.There was no recurrence or metastasis two years and two months after the combined treatment.
