Meningiomas of the lateral skull base: neurotologic manifestations and patterns of recurrence

The eradication of basicranial meningiomas by traditional surgical techniques is often hindered by neoplastic entanglement with critical neurovascular structures. Apparent, complete tumor resection is frequently followed by extensive, yet clinically silent, recurrent disease with local infiltration of bone, cranial nerves, and brain. Fifty-five cases of sphenoid wing or parasellar meningioma were analyzed to identify clinical manifestations suggestive of early tumor recurrence. Regrowth patterns were then defined according to preoperative radiographic and intraoperative surgical findings. Medial tumor regrowth, involving the cavernous sinus, caused neurapraxia of cranial nerves III, IV, or VI, with associated diplopia or ophthalmoplegia. Inferior (caudal) regrowth of disease involved the infratemporal fossa, pterygomaxillary space, or paranasal sinuses by bony erosion of the middle cranial fossa floor or through natural anatomic foramina and fissures. Such inferior extension was manifested clinically by facial hypesthesia, trismus, and referred otalgia caused by trigeminal nerve involvement and by autophony or serous otitis media related to eustachian tube obstruction. Posterior tumor regrowth occurred along the petrous bone and horizontal carotid canal, resulting in internal auditory meatus erosion and cerebellopontine angle extension with associated tinnitus, hearing loss, unsteadiness, and occasional facial twitching. While the clinical and radiographic evaluations of any patient with a suspected recurrent basicranial meningioma are critical in planning the method and magnitude of reoperation, an understanding of potential recurrence patterns can be used in devising more extensive, combined approaches that may allow complete tumor extirpation at the initial surgical intervention.