Sinonasal carcinomas

Malignant neoplasms of the sinonasal tract encompass a wide variety of epithelial, lymphoid and mesenchymal tumours. The separation and classification of epithelial or neuroepithelial tumours is sometimes challenging, especially when treatment and prognosis are different. Squamous cell carcinoma, keratinizing or non-keratinizing and, usually, the poorly differentiated type need to be separated from sinonasal undifferentiated carcinoma, lymphoepithelial carcinoma, neuroendocrine carcinoma and olfactory neuroblastoma. Whereas melanoma and lymphoma are also included in the broad differential, along with primitive neuroectodermal tumours and rhabdomyosarcomas, the focus of this commentary will be to present the major clinical, radiographical, histological, immunohistochemical, ultrastructural and molecular features which allow for separation of the principle mucosal epithelial neoplasms of the sinonasal tract.