Abstract
We describe a 66-year-old man with mucoepidermoid carcinoma arising in the accessory parotid gland. A painless mass in the left cheek had been gradually growing for five years. The patient was referred to our hospital after an incisional biopsy at another hospital indicated a diagnosis of mucoepidermoid carcinoma. Both CT and MRI showed a solid, 18 × 14 mm tumor lying on the masseter muscle, but which did not affect the parotid gland. In light of the clinical background in addition to the radiological and histological findings, mucoepidermoid carcinoma of the accessory parotid gland was suspected. The tumor was surgically removed through a midcheek incision. The buccal branch of the facial nerve and Stensen's duct were involved in the tumor and were sacrificed. The tumor was composed of mucous and epidermoid cells leading to a pathological diagnosis was low-grade mucoepidermoid carcinoma. Slight paresis of the buccal branches resolved two months after surgery. The patient has remained free of recurrence during seven months of follow-up.
The accessory parotid gland is found in 20-70% of individuals and it comprises salivary tissue that is separated from the main parotid gland and lies on the masseter muscle. However, accessory parotid tumors are rare. The frequency of malignant accessory parotid gland tumors is higher than that of malignancies of the main parotid gland tumor, the reported frequency of which is 42-52%. Although the incidence of accessory parotid gland tumors is low, the possibility of such tumors should be considered in a differential diagnosis of a cheek mass.
