An extremely rare type of carcinoma in the hypopharynx case report of epithelial myoepithelial carcinoma in the pyriform sinus

Abstract

Hypopharyngeal and laryngeal cancers account for about one third of all head and neck neoplasms, affecting about 15,000 Americans per year. The pyriform sinus is located in a posterolateral position in relation to the larynx. It is part of the pharynx. Anatomically, its borders are the thyroid cartilage and thyrohyoid membrane laterally, and the cricoid cartilage and aryepiglottic fold medially. Its superior limits are the free edge of the aryepiglottic fold and glossoepiglottic fold.1 Inferiorly, it ends at the cricopharyngeus muscle, which is the most inferior structure of the pharynx and serves as the valve at the top of the esophagous. Epithelial-myoepithelial carcinoma (EMC) is a rare neoplasm, first described in 1972 by Donath et al.,2 EMC accounts for ~1% of epithelial salivary gland tumors, with the majority of cases arising in the parotid gland. Epithelial myoepithelial carcinomas are considered the rarest type to occur in salivary glands, with less than 600 cases reported in the literature since its initial description in 1972.3 Thus, the incidence to occur among the pharynx and larynx becomes even rarer. Upon literature review, only one case of epithelialmyoepithelial carcinoma in the hypopharynx was reported in 2014.4