Epithelial-myoepithelial carcinoma of the hypopharynx: A rare case.

Epithelial-myoepithelial carcinoma (EMC) is a rare neoplasm, which predominantly arises in the parotid gland. EMC is characterized by two types of cells; myoepithelial and epithelial cells arranged in well-defined tubules. A 48-year-old male with a six-month history of dysphagia presented with a 2-cm-diameter mass in the left posterior wall of the hypopharynx. Histopathological examination revealed that the tumor cells were arranged in duct-like structures with an inner layer of ductal cells and an outer layer of clear cells. Immunohistochemically, the outer layer of clear cells stained positive for calponin, p63 protein, glial fibrillary acidic protein, S-100 protein and smooth muscle actin, which is consistent with a myoepithelial phenotype. The inner layer stained positive for cytokeratin and cytokeratin-7, which is consistent with an epithelial phenotype. The tumor was excised and no recurrence or metastasis was found 27 months following surgery. To the best of our knowledge, this is the first case of EMC described that has arisen from the hypopharynx.