Multiple primary pleomorphic adenomas in a single parotid gland: report of a new case.

The development of multiple primary pleomorphic adenomas in a single parotid gland is extremely rare in previously untreated patients, as only nine cases have been previously reported. In this article, we report the tenth such case, which occurred in an 87-year-old Japanese women. We also report the results of our 7-plus-year review of the types of parotid tumors seen at our institution. We identified 98 tumors in 89 patients; pleomorphic adenomas were the most common tumors, accounting for 45.9% of the total.