Sinonasal undifferentiated carcinoma: Report of a case and review of literature

Sinonasal undifferentiated carcinomas (SNUC) are highly aggressive lesions arising in the superior nasal cavity and paranasal sinuses. The differential diagnosis may be wide since a range of similar lesions may present at this site. Recently the criteria for diagnosis of SNUC has been clarified. Histologically they show marked pleomorphism, mitotic activity and necrosis with no evidence of squamous or glandular differentiation or of rosettes. They express low molecular weight cytokeratins and are typically negative for S-100 and neuroendocrine markers. They do not express EBV.