Clear cell carcinoma of the nasal cavity: A case report from histopathological viewpoint.

We report an extremely rare case of primary clear cell carcinoma (CCC), not otherwise specified (NOS) of the nasal cavity. An 80-year-old woman was referred to our hospital with left nasal obstruction caused by a nasal cavity tumor. The tumor was resected completely with lateral rhinotomy approach. Histopathological examination revealed CCC. CCC metastasis from renal cell carcinoma (RCC), which is at the top of differential diagnosis, was ruled out by the absence of renal tumor at computed tomography (CT). Also, immunohistochemical results of the specimen with vimentin negative and CK7 focally positive excluded the possibility of RCC metastasis. The patient is free from recurrence 1 year after the surgery, and there is no evidence of RCC. In this report histopathological characteristics, especially immunohistochemical properties of primary CCC, NOS of the nasal cavity are presented together with some clinical features of this rare tumor. Also, we refer to histopathogenesis of primary CCC of nasal cavity in relation to myoepithelial carcinoma. Histopathological discussion is further extended to include other CCC and CCC-resembling histologies to confirm the uniqueness of the present case.