A case of acinic cell carcinoma of the parotid gland presenting as a cyst

Acinic cell carcinoma is a rare tumor that generally arises from the parotid gland. The differential diagnosis of this carcinoma from other diseases of the parotid gland is difficult preoperatively. The authors report their experience with a 25-year-old woman with an acinic cell carcinoma arising from the right parotid gland. She presented with a mass situated anterior to the right ear. The mass measured 38×28mm. An exploratory puncture was performed, and the serous contents of the mass were aspirated. CT revealed a cystoid lesion that was considered to be nononcogenic. It was diagnosed to be a parotid gland cyst and excised. However, histopathological examination revealed an acinic cell carcinoma. The patient is being followed up, and there have been no signs of recurrence.