Epithelial-Myoepithelial Carcinoma with High Grade Transformation of Nasal Cavity

Abstract

High grade transformation in epithelial-myoepithelial carcino¬ma is a recently defined entity with only a few cases reported in the literature. We present a 59 years old female patient with a polypoid lesion in nasal cavity, together with clinical com¬plaints as recurrent epistaxis and stuffiness. Histological and immunohistochemical examination of the surgically excised le¬sion revealed a diagnosis of epithelialmyoepithelial carcino¬ma with high grade transformation. Epithelial-myoepithelial carcinoma originates from salivary glands, mainly parotid gland. Other affected sites are submandibular gland and minor sali¬vary glands. Epithelialmyoepithelial carcinoma is characterized by double layered duct-like structures. Greater cytologi¬cal atypia, higher mitotic rate, presence of necrosis and loss of the biphasic ductlike structures are features of high grade transformation. Local recurrence and cervical lymph node me¬tastases are seen with low incidence in classical epithelial-myoepithelial carcinoma, whereas epithelial-myoepithelial carcinoma with high grade transformation has high tendency for lymph node and distant metastases.