上皮一肌上皮癌（EMC）是一种罕见的来源于诞腺间介管的肿瘤。发生于易窦的EMC非常少见。作者报道了唯一的1例发生在上颌窦并向硬腔和鼻腔延伸的肿瘤，讨论临床和组织病理特点。患者女性，65岁，鼻塞1年。查体发现右侧鼻腔有一硬性肿物，已经向口腔硬瞎延伸。组织活俭诊为多形 Epithelial myoepithelial neoplasia (EMC) is a rare tumor derived from interstitial cells. The EMC that occurs in the sinus is very rare. The authors reported the only tumor that occurred in the maxillary sinus and extended to both the hard and nasal cavities, discussing clinical and histopathological features. Female patient, 65 years old, stuffy nose for 1 year. Physical examination found that the right nasal cavity has a hard tumor, has been extended to the oral hard blind. Organization frugally diagnosed as polymorphism