Epithelial papilloma and squamous cell carcinoma of the nasal cavity and paranasal sinuses.A clinicopathological study

Seventeen cases of intranasal epithelial tumors are reviewed. Thirteen were epithelial papillomas and four were squamous cell carcinomas associated with epithelial papillomas. In two cases followed over a 10 year period, transformation from an initial papilloma into a carcinoma was demonstrated. The histopathologic caracteristics of these lesions are described including the presence of prominent palisading and intraepithelial nesting in some tumors. The literature was reviewed for reports of carcinoma arising in previously benign epithelial papillomas. We suggest that squamous cell carcinoma may occasionally arise from a previously benign epithelial papilloma.