Malignant inverted papilloma characterized by proptosis

An inverted papilloma, presumably originating in the ethmoid sinus, was characterized by proptosis in a 67-year-old man. Clinically and radiologically it simulated a primary orbital tumor. Squamous carcinoma appeared in this lesion; irradiation and exenteration, 3 1/2 years after onset of symptoms, failed to prevent fatal intracranial extension.