Epithelial-myoepithelial carcinoma – Report of a case arising in the nasal cavity

Abstract

We present an extremely rare case of epithelial-myoepithelial carcinoma (EMC) arising in the nasal cavity. The patient was a 56-year-old Japanese male with a polypoid tumour arising from the nasal septum. Histopathological examination revealed the tumour to consist of a solid proliferation of clear-cells and, in some areas, small or elongated duct structures with a double-layered arrangement of inner cuboidal cells and outer clear-cells. Dual differentiation toward myoepithelial and ductal cells were confirmed immunohistochemically. The occurrence of EMC in the nasal cavity is possible and this entity should be generally recognized by surgical pathologists, not only those engaged in head and neck surgery.

Histomorphological Investigation Regarding to Malignant Transformation of Pleomorphic Adenoma (So-called Malignant Mixed Tumor) of the Salivary Gland Origin. Special Reference to Carcinosarcoma.

“…Epithelial-myoepithelial carcinoma (EMC) : This tumor is a previously reported as glycogen-rich adenoma, glycogen-rich adenocarcinoma, clear cell adenoma, clear cell adenocarcinoma [28] and has been added as a category of carcinomas in the current WHO histological classification. It is a rare tumor, constituting 1.1% of the epithelial salivary gland tumors [29] and, formerly regarded as a lowgrade carcinoma [28,30] Yamamoto et al (1988) [35] have presented a possible explanation in comparison with so-called scar cancer of the lung as follows: at first, hyalinization through long-standing duration causeshypooxygenic status in the mass, which damages benign neoplastic cells. The cells repeatedly regenerate and, in the end, transform into those malignant through the regenerative procedure.…”

Epithelial‐myoepithelial carcinoma of the maxillary sinus: A rare case

“…There are cases reported arising from submandibular gland and minor salivary glands located in various sites. Very limited cases are reported arising from nasal cavity,9–11 paranasal sinus,1 nasopharynx,12 cheek,13 palate,14, 15 base of tongue,16 subglottis,17 tracheobronchial tree,18 lacrimal gland,19 and liver 20. Theoretically, they can arise in any organ where a double layer duct pattern exists and are considered to be a variant of clear cell carcinoma.…”

Sinonasal epithelial-Myoepithelial carcinoma-A rare entity

“…They are also known as clear cell adenoma, clear cell carcinoma, tubular carcinoma, glycogen rich adenoma, glycogen rich adenocarcinoma and salivary duct carcinoma. It is predominantly a tumor of the parotid gland, while rare sites of occurrence includes submandibular gland, sinonasal tract, trachea, bronchus, lung, breast and lacrimal gland 3,4,5 .…”

“…Very few cases of EMC arising in unusual sites like breast, lacrimal glands, nose, paranasal sinuses, trachea, bronchus and lung have been reported till date 3,4,5 . We here present an extremely rare case of sinonasal EMC in a young male patient.…”