Sinonasal non-keratinizing squamous cell carcinoma with nasal skin extension as the initial presentation

Sinonasal non-keratinizing squamous cell carcinoma (SCC), previously designated as transitional cell carcinoma or cylindrical cell carcinoma, is an uncommon malignant neoplasm with distinct histopathological features, considered to be a low-grade malignancy that usually occurs in elderly patients. Extensive local invasion is uncommon. Here we report a case of 90-year-old woman whose original presentation was as erythematous nasal skin nodules, biopsy of which showed a dermal tumor with features of sinonasal non-keratinizing SCC. No epidermal dysplasia was present. A subsequent computed tomography scan confirmed the presence of an endophytic tumor on the nasal sidewall. The initial presentation of sinonasal non-keratinizing SCC as a skin lesion is previously unreported to our knowledge. Diagnosis in this context requires accurate evaluation of the histopathology as well as a comprehensive knowledge of pathology specific to this anatomic location.