Myoepithelioma in the floor of the mouth: A rare case report with immunohistochemical findings

Abstract

Myoepithelioma (ME) is a rare benign tumor of the salivary glands and is usually seen in the parotid gland and the minor salivary glands of the soft palate and represents <1% of all salivary gland tumors. It was once considered to be a type of pleomorphic adenoma, but MEs are today believed to be relatively more aggressive. There are distinct histological and immunohistochemical characteristics of the tumor which aid in the diagnosis. The present case report describes an asymptomatic mass that arose in the floor of the mouth of a 59-year-old female patient which is a very rare location. An analysis of the immunohistochemical profile of the tumor cells showed positivity for S-100 protein and pancytokeratin. MEs should be considered in the differential diagnosis of swellings of the floor of the mouth along with several benign and malignant soft tissue neoplasms.