Oncocytic and oncocytoid tumors of the salivary glands.

Primary pink cell tumors of the salivary glands constitute a heterogeneous group of benign and malignant lesions characterized by tumor cells with abundant eosinophilic cytoplasm. These tumors are composed predominantly of oncocytic, epidermoid, or myoepithelial cells. Tumors with a significant oncocytic component include Warthin's tumor, oncocytoma, and oncocytic carcinoma. An epidermoid component can be seen as a metaplastic change or as a true cellular constituent of a mucoepidermoid carcinoma. Myoepithelial cells may have an epithelioid character and as a consequence may impart a pink cell appearance in pleomorphic adenoma, myoepithelioma, and myoepithelial carcinoma. Usually most of these tumors are fairly distinct morphologically and do not present diagnostic dilemmas. In select circumstances, especially when dealing with a limited tissue sample, a systematic approach with an appropriate immunohistochemical panel should be used in order to arrive at a correct diagnosis. Accurate assessment is the key in the subsequent management and follow-up of these patients.