Myoepithelial carcinoma (malignant myoepithelioma): first report of an occurrence in the maxillary sinus

Aim: We document for the first time the occurrence of a malignant myoepithelioma at a site other than within the major and minor salivary glands. Methods and results: A 67-year-old male presented with progressive symptoms and signs of a space-occupying lesion in the right maxillary sinus. An initial biopsy identified a malignant (myo)epithelial lesion and a radical maxillectomy was performed. Histology, supplemented by immunohistochemistry, confirmed the prescence of a malignant myoepithelioma. Conclusion: Malignant myoepithelioma is a very rare tumour composed almost exclusively of myoepithelial cells and, to date, has only been described arising in the the major and minor salivary glands. A variety of tumours of salivary tissue have been reported within the head and neck area at sites outside the major and minor salivary glands, probably arising within accessory salivary tissue. We report the first case of a malignant myoepithelioma occurring in the maxillary sinus, also presumably arising in accessory salivary tissue in this location.