INTRACRANIAL INVERTING PAPILLOMA

Background. Inverting papillomas usually originate from the lateral wa ll of the nose and sporadically from the ethmoid, maxillary, sphenoid, or frontal sinuses. Intracranial extension and dural penetration is r are and often associated with recurrent disease that has degenerated i nto squamous cell carcinoma. A case of inverting papilloma with dural penetration in the absence of malignant degeneration has prompted an i nvestigation into the incidence and treatment of dural invasion by ben ign inverting papilloma. Methods. A literature search revealed 1468 ca ses of inverting papilloma. A detailed analysis was performed to obtai n data on the incidence of intracranial invasion. Results. Of the 1468 cases, 5 were noted to be associated with intracranial extension with out histologic evidence of malignancy (0.34%). Treatment consisted of surgery alone in 3, radiotherapy in 1, and combined therapy in the las t patient. Dural invasion was documented histopathologically in one ca se. Conclusion. Intracranial extension and dural penetration of benign inverting papilloma is extremely rare, and a uniform treatment plan h as not been established. Further investigation is necessary in the pat hophysiology and management of intracranial inverting papilloma. (C) 1 996 John Wiley & Sons, Inc.