Introduction: When vestibular schwannoma (VS) collides with meningioma at the cerebellopontine angle (CPA), a particular threat occurs. Sudden acceleration of tumor growth and unpredictable involvement of cranial nerves results in a special environment that aggravates management. The goal of this study was to analyze the extent of resection, postoperative facial and cochlear function, surgical strategy, and survival rates in patients with neurofibromatosis type 2 (NF2) with meningioma-vestibular schwannoma (M-VS) collision tumors.
Methods: A total of 1284 VS, including 165 NF2 VS were operated at our department between January 2004 and May 2018. Out of these cases, a group of six NF2 patients with seven M-VS collision tumors was found following careful analysis of neuroradiological data and pathological and surgical reports. Patients were evaluated for extent of tumor resection and, furthermore, postoperative facial and hearing function.
Results: Six patients with NF2 with seven M-VS collision tumors were included in this study. Mean age was 32 ± 8.2 years. A gross total resection (GTR) of both colliding tumors was achieved in only one case, a GTR of the meningioma and a subtotal resection (STR) of the VS in four cases and in two cases only, the meningioma was removed. In five of the cases, facial function was intact or good (House and Brackmann grades I-II) at long-term follow-up (mean follow-up 22 months). No mortality occurred during follow-up.
Conclusions: Collision between M and VS at the CPA is a particular phenomenon in NF2 patients that may aggravate the situation with less favorable surgical outcome than NF-2 VS without meningioma.
Keywords: Cerebellopontine angle; Collision tumor; Meningioma; Neurofibromatosis type 2; Vestibular schwannoma.