[A case of polymorphous adenocarcinoma in the right parotid gland].

The nature of adenocarcinomas of parotid gland origin seems to be still unclear because of the rarity of this lesion. A 65-year-old man with a "polymorphous adenocarcinoma" of the parotid gland is presented. This tumor is characterized by a marked diversity in the histologic manifestations, presenting dominantly solid, tubular, pseudoadenoid cystic sarcomatoid patterns. The tumor cells showed distinctive signs of high grade malignancy such as the occurrence of mitotic figures and involvements of lymphatic vessels and/or blood vessels. "Polymorphous adenocarcinoma" is a histologically distinctive neoplasm unlike other adenocarcinomas of parotid gland origin.