Recurrent extensive plasmacytoid myoepithelioma of the sinonasal cavity.

Myoepithelioma is an uncommon benign neoplasm that most likely occurs in the parotid gland. Extra-salivary myoepitheliomas are rare, with less than 10 cases reported in the sinonasal cavity. We present a rare case of benign myoepithelioma with recurrent behavior, abundant extensions to adjacent structures, and resistant to treat clinical course, which influenced the patient's quality of life for more than 18 years. Histologic, immunohistochemical, and the potential differential diagnoses are discussed. The patient refused to undertake any more treatments, but after 15 months of follow-up, the lesion did not progress further.