Perioperative Differences between Large Acoustic Neuromas and Cerebellopontine Angle Meningiomas

Objectives: To compare the clinicoradiographic features of acoustic neuroma (AN) and meningioma (MEN) of the cerebellopontine angle. To assess the perioperative results following the surgical management of these two patient populations.

Study Design: A retrospective review of patients treated between 1995 and 2006 for large (> 3 cm) AN or MEN of the cerebellopontine angle.

Setting: Tertiary-care, academic medical center.

Interventions: Clinical and radiographic assessment and perioperative results.

Outcome Measures: The extent of tumor resection, postoperative complications, and long-term results.

Results: The review included 95 patients with AN and 32 cases of MEN. Tinnitus and hearing loss were more common in the AN patients, while facial numbness was noted more often in the MEN group. A narrow intracanalicular enhancement (“tail sign”) on MRI helped identify MEN in 30 of the 32 cases. Total tumor removal was achieved in 90 of 95 (95%) of the AN cases, but in only 20 of 32 (63%) of the MEN patients. Anatomic facial nerve preservation was achieved in all AN cases and in 30 of 32 (94%) of the MEN group. Tumor regrowth requiring additional surgery and/or radiotherapy occurred in 3 MEN patients, but in none of the AN individuals. The mean follow-up period was 5.5 years.

Conclusions: MRI is very accurate in differentiating AN from MEN of the cerebellopontine angle. Total tumor resection and facial nerve preservation were more difficult in the MEN group, but only 3 of these 32 patients required additional treatment for regrowth of residual disease.