High-Grade Glioma is Not a Feature of Neurofibromatosis Type 2 in the Unirradiated Patient

BACKGROUND: The Manchester criteria for neurofibromatosis type 2 (NF2) include a range of tumors, and gliomas were incorporated in the original description. The gliomas are now widely accepted to be predominantly spinal cord ependymomas. OBJECTIVE: To determine whether these gliomas include any cases of malignant glioma (WHO grade III and IV) through a database review. METHODS: The prospective database consists of 1253 patients with NF2. 1009 are known to be alive at last follow-up. RESULTS: There was a single case of glioblastoma multiforme (GBM; World Health Organization grade IV) in the series and no WHO grade III gliomas. The GBM was in a patient who had previously undergone stereotactic radiosurgery for a vestibular schwannoma. CONCLUSION: High-grade gliomas are not a feature of NF2 in the unirradiated patient and should be excluded from the diagnostic criteria.