Bilateral parotid gland basal cell adenomas. Case report.

We report a 65-year-old female with basal cell adenomas arising in the left and right parotid glands and review the literature. Diagnosis was based on clinical features, ultrasonographic and CT findings as well as histopathological examination. Parotid tumours usually arise on one side and bilateral occurrence is rare, accounting for 1-3% of all parotid tumours. Most bilateral parotid tumours are Warthin's tumours and pleomorphic adenomas, and bilateral basal cell adenomas of the parotid glands are very rare and only 5 cases including ours have been reported. The exact mechanisms contributing to the development of bilateral parotid tumours remain unknown. We speculate on the involvement of environmental and genetic factors since the histological features of both parotid tumours are identical in most cases. Copyright 2000 S. Karger AG, Basel