Biallelic NF2 gene inactivation is common in sporadic and in neurofibromatosis type 2 (NF2)-related meningiomas. We show that, beginning at four months of age, thirty percent of mice with arachnoidal cell Cre-mediated excision of Nf2 exon 2 developed a range of meningioma subtypes histologically similar to the human tumors. Additional hemizygosity for p53 did not modify meningioma frequency or ...

Neurofibromatosis type 2 (NF2) is a rare syndrome characterized by bilateral vestibular schwannomas, multiple meningiomas, cranial nerve tumors, spinal tumors, and eye abnormalities. NF2 presents unique challenges to the otologist because hearing loss may be the presenting complaint leading to the diagnosis of the disorder. Care of patients with NF2 requires knowledge of all tumors and symptoms...

OBJECTIVE To screen for NF2 mutations in people with meningiomas. METHODS Lymphocyte or tumour DNA was analysed from 46 individuals from 36 families who presented with a meningioma at age < or =15 years without vestibular schwannoma (VS), or who had multiple meningiomas in adulthood before the diagnosis of VS. RESULTS Eight of 13 people with meningioma and other features of neurofibromatosi...

OBJECTIVE Clinically validated biomarkers for neurofibromatosis 1 (NF1), neurofibromatosis 2 (NF2), and schwannomatosis (SWN) have not been identified to date. The biomarker working group's goals are to (1) define biomarker needs in NF1, NF2, and SWN; (2) summarize existing data on biomarkers in NF1, NF2, and SWN; (3) outline recommendations for sample collection and biomarker development; and ...

General introduction to the neurofibromatoses The diseases traditionally known as neurofibromatosis have now been formally separated into two types: neurofibromatosis type 1 or NFl (the type described by von Recklinghausen) and neurofibromatosis type 2 or NF2 (a much rarer form).' It is now recognised that although they have overlapping features, including an inherited propensity to neurofibrom...

Neurofibromatoses are a set of inherited disorders, designated as neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2), and schwannomatosis, that tend to result in the development of benign tumors of the nerve sheath. The 3 entities are distinguished by specific clinical features and are due to mutations in distinct genes (Table 1). Neurofibromatosis type 1 is the most common of the d...

Hemizygosity for the NF2 gene in humans causes a syndromic susceptibility to schwannoma development. However, Nf2 hemizygous mice do not develop schwannomas but mainly osteosarcomas. In the tumors of both species, the second Nf2 allele is inactivated. We report that conditional homozygous Nf2 knockout mice with Cre-mediated excision of Nf2 exon 2 in Schwann cells showed characteristics of neuro...

Ependymomas and astrocytomas commonly have allelic losses of chromosome 22q, which suggests the presence of a glioma tumor suppressor gene on 22q. A candidate tumor suppressor gene on 22q is the neurofibromatosis 2 (NF2) gene since NF2 patients have an increased susceptibility to ependymomas and astrocytomas. Using single strand conformation polymorphism analysis and direct DNA sequencing, we s...

OBJECTIVE Individuals with the neurofibromatosis type 2 (NF2) cancer predisposition syndrome develop spinal cord glial tumors (ependymomas) that likely originate from neural progenitor cells. Whereas many spinal ependymomas exhibit indolent behavior, the only treatment option for clinically symptomatic tumors is surgery. In this regard, medical therapies are unfortunately lacking due to an inco...

Two cases of multiple concomitant CNS tumors of different histologic types are presented.  One was a case of neurofibromatosis type 2 (NF2) with 6 CNS tumors, and the other a case of 4 CNS tumors without any evidence of NF. To our knowledge, there is no report of concomitant occurrence of 6 CNS tumors in the medical literature. Neuroradiological  and operative findings are illustrated and discu...