Myoepithelioma of the Nasal Septum: A Rare Case of Extrasalivary Gland Involvement.

Introduction. The myoepithelioma is a rare benign tumor, most frequently found in the salivary glands. The extrasalivary gland involvement is even rarer and few cases involving the nasal cavity have been reported in the literature. Case Report. MES, a 54-year-old woman, complaining of progressive nasal obstruction and mild epistaxis through the right nostril which had developed 1 year previously. Computed tomography scan showed tumor with heterogeneous contrast enhancement occupying the right nasal cavity, moving contralaterally in the nasal septum. Excisional biopsy was performed through endoscopic surgery of the mass that was inserted at the nasal septum. Pathological and immunohistochemical exams concluded myoepithelioma. Discussion. The main symptoms of nasal myoepitheliomas are nasal obstruction and epistaxis. Immunohistochemistry is necessary to confirm the diagnosis, typically positive for cytokeratin and S-100, calponin, smooth muscle actin, myosin, vimentin, glial fibrillary acidic protein (GFAP), and carcinoembryonic antigen. The main marker for myoepithelioma is the S-100 protein. In our case, it was positive for cytokeratin, S-100, calponin, actin smooth muscle, and GFAP. In all cases reported in the literature surgical treatment was performed and the recurrence was associated with incomplete tumor resection. Final Comments. The myoepithelioma is a rare differential diagnosis of nasal tumors and its treatment is the total lesion excision.