Synchronous unilateral parotid neoplasms of different histologic types.

Synchronous parotid neoplasms are rare. Unilateral, synchronous neoplasms of two separate and histologically distinct types are extremely unusual. Our review of the literature revealed 31 previously reported cases. We add two additional cases found in 291 parotid neoplasms seen in our institutions over the last 10 years; both including a pleomorphic adenoma and a Warthin's tumor. This combination was found in 15 of 33 cases, while Warthin's tumors were found in association with another tumor in 24 of 33 reported cases (82%).