Management of intracranial meningiomas secondarily involving the infratemporal fossa: radiographic characteristics, pattern of tumor invasion, and surgical implications.

OBJECTIVE: Intracranial meningiomas extending into the infratemporal fossa (ITF) are uncommon. This series describes the radiographic characteristics, histological pattern of invasion, and implications for surgical treatment of intracranial meningiomas.

METHODS: Nine patients (median age, 52 yr) underwent resection of a transcranial meningioma extending into the ITF. Five patients (56%) had undergone a previous resection; however, none had involvement of the ITF. Four patients (44%) had received prior radiation therapy to the area.

RESULTS: Preoperative neuroradiography uniformly showed erosion of the middle fossa floor and extension of the tumor through cranial base foramina. Histological results indicated tumor invasion of the middle fossa floor and skeletal muscle in all patients. Perineural invasion was present in four patients. Mucosal invasion was observed in six patients. A middle fossa/zygomatic approach provided access to the intra- and extracranial components of the tumor, as well as the cavernous sinus, ITF structures, paranasal sinuses, and nasopharynx. Reconstruction was performed using the temporalis muscle, which provides a vascularized flap between exposed mucosa and the carotid artery and intradural structures. A gross total resection was performed in seven patients (78%). Postoperative complications included soft tissue ischemia (one patient), worsening of preoperative cranial neuropathy (two patients), and lower extremity deep vein thrombosis (two patients). One patient died 2 months postoperatively from a pulmonary embolus. Two patients had recurrence of intracranial meningiomas extending into the ITF at 2 and 3 years postoperatively, necessitating further resection.

CONCLUSION: Understanding the pertinent clinical and morphological aspects of meningioma transcranially involving the ITF is essential to surgical treatment of patients with this condition.