Synchronous benign and malignant salivary gland tumors in ipsilateral glands: a report of two cases and a review of literature.

Background: Ipsilateral salivary gland tumors of different histologic types are rare and make up less than 0.3% of all salivary gland neoplasms. Only nine cases of synchronous benign and malignant ipsilateral parotid gland tumors have been described in the literature.

Methods: Two additional cases of synchronous benign and malignant neoplasms in the parotid gland are reported and discussed with a review of literature.

Results: Our first case describes a pleomorphic adenoma and a salivary duct carcinoma, an entity not previously reported in the literature. The second case documents the most common benign and malignant ipsilateral parotid gland neoplasm reported in this case series, a Warthin's tumor and a mucoepidermoid carcinoma.

Conclusions: Synchronous salivary gland tumors exhibiting both benign and malignant components are uncommonly observed, with only nine cases published to date. We describe two additional cases of a synchronous benign and malignant ipsilateral parotid gland tumor.