Synchronous bilateral multifocal acinic cell carcinoma of parotid gland: case report and review of the literature.

A 55-year-old woman presented with a 2-year history of slow growing painless masses in both sides of the preauricular area. Ultrasound scanning of the bilateral parotid region revealed multiple tumors in both sides of the parotid gland. After superficial parotidectomy, selective neck dissection of levels II and III were performed on the left side of the parotid gland, and superficial parotidectomy was performed on the right side. Histopathologic examination revealed both of the sides of parotid gland tumors to be acinic cell carcinoma. We discuss the clinicopathologic findings of synchronous bilateral multifocal acinic cell carcinoma of the parotid gland.