Abstract
Myoepithelioma is a rare lesion which has been reported mainly in the salivary glands. In the nasal cavity and paranasal sinuses, its occurrence is exceedingly rare and, to our knowledge, only 5 cases have been reported. We recently treated a 31-year-old female with myoepithelioma of the ethmoid sinus who presented with swallowing disturbance because of a rapidly expanding choanal polyp. We performed a Caldwell-Luc operation and found the tumor expanding into the ethmoid sinus. For diagnosis, immunohistochemical examination was effective in addition to H-E staining.