Inverting papilloma of the nose and paranasal sinuses.

Inverting papilloma of the nose and paranasal sinuses has been classified as a true neoplasm by most authors. It is distinct from the ordinary nasal polyps in that it has a different cause, different histologic features, a higher recurrence rate, and is occasionally associated with carcinoma. This study includes 57 patients seen over a 30-year period who had inverting papilloma and for whom the history, clinical and radiologic findings, treatment methods, pathologic sections, and recurrences were analyzed. Features associated with higher recurrence rate were epithelial atypia and extent of lesions. Females showed higher recurrence rates than males. External approaches (lateral rhinotomy) reduced recurrence remarkably compared with transnasal removal (13 percent versus 45 percent). Four patients had associated carcinoma with inverting papilloma, and more extensive operations were perfomred in these cases; one patient died of the tumor. Radical aggressive treatment and careful follow-up are advocated because of the higher recurrence rate after inadequate removal and because of possible malignant transformation.