Malignant myoepithelioma. Clinicopathological and immunohistochemical characteristics.

A malignant myoepithelioma arising in the submucosal accessory glands of the oral cavity of a 23-year-old woman is reported. The patient was very young compared to the cases in the literature, and the tumour had an unusual vestibular location. A false diagnosis of pleomorphic adenoma had been made by fine needle aspiration biopsy. The surgery comprised a wide tumour excision, but neck dissection was not indicated. The final histologic diagnosis was malignant myoepithelioma. Immunohistochemically putative myoepithelial markers were highly expressed.