Clear Cell Myoepithelioma - A Rare Presentation in Nasal Cavity

Abstract

Myoepitheliomas are predominantly tumors of salivary glands constituting less than 1% of all salivary gland tumors. A 65 year old women presented with bleeding unilateral mass for 03 months. Contrast Enhanced Computed Tomography (CECT) revealed a heterogeneously enhancing mass lesion arising from right anterior ethmoid air cells and filling the right nasal cavity entirely. Endoscope guided endoscopic biopsy was performed. Histopathological examination showed a well circumscribed tumour arranged in small glands and sheets. Tumor cell were immunopositive for S100 (Ib), Cytokeratin (CK) and Vimetin (focally ) while negative for chromogranin, synaptophysin, CD 10 and Smooth Muscle Actin (SMA). MIB-Labelling Index was <5%. With these features a diagnosis of clear cell myoepithelioma was made. Nasal myoepithelioma is an extremely rare low-grade neoplasm. Nasal myoepitheliomas are composed of myoepithelial cells with solid, myxoid or reticular patterns of growth. The cells themselves may be clear-cell type, spindle-shaped, plasmacytoid and epithetlioid. In all reported cases of myoepithelioma, surgery was the mainstay treatment. Partial maxillectomy via a lateral rhinotomy approach, Caldwell-Luc procedure has been recommended for patients who were suspected to have a low-grade sarcomatous neoplasm. Only five cases have been reported in sinonasal region. We report the second case to be managed endoscopically. We report an extremely rare benign tumor of nasal cavity (clear cell myoepithelioma) which was managed endoscopically with recurrence within 6 months. The recurrence was also managed endoscopically. This case highlights the varied malignancies which may be encountered in sinonasal region.