Mucoepidermoid carcinoma arising in the accessory parotid gland.

A rare case of a 9-year-old female with mucoepidermoid carcinoma arising in the accessory parotid gland is reported. She had complained of a painless and round mass of the left cheek for a duration of 14 months. Sialography, ultrasonography, CT scan and MRI were performed preoperatively. Sialography revealed a small duct separating from the Stensen's duct. CT and MRI showed that the tumor with smooth outline was lying on the masseter muscle and detached from the main parotid gland. The preoperative diagnosis was an accessory parotid gland tumor. The tumor was removed without facial nerve injury via standard parotidectomy incision. The tumor was composed of mucous and epidermoid cells. The pathological diagnosis was low-grade mucoepidermoid carcinoma.