Intracranial Inverted Papilloma. A Case Report

Abstract

A case of a recurrent inverted papilloma with intracranial extension will be presented and the literature on intracranial inverted papilloma will be discussed. Inverted papilloma confined to the sphenoid sinus is an uncommon finding. Intracranial extension is even more rare and in such cases is frequently associated with coexisting squamous cell carcinoma. Reviewing the reported cases of “pure” inverted papilloma with intracranial extension, all were localized in the anterior skull base. In this case an extension to the infratemporal fossa, orbit, middle, and eventually posterior cranial fossa was found a few years after various transnasal procedures for recurrent sinonasal inverted papilloma. During the first intracranial approach, the tumor extended to the orbit, the cavernous sinus, and the extradural compartment of the floor of the middle fossa, most probably by extension via the foramen rotundum and ovale. Within months, a large intradural recurrence was seen in the temporal lobe and cerebellopontine angle. A subtotal resection was performed followed by radiotherapy. Eighteen months later, the growing mass in the posterior cranial fossa and cerebellopontine angle was subtotally resected. No histological evidence of malignancy was found in the specimens of each procedure. DNA analysis was positive for oncogenic type human papilloma virus (HPV). Intracranial inverted papillomas show aggressive behavior with high morbidity and even high mortality. Most patients with intradural extension die within 1 year, regardless of treatment. This patient is still alive with severe unilateral deficits of all cranial nerves.