The Neurofibromatoses

Abstract The neurofibromatoses include neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2), and schwannomatosis. These are genetically distinct tumor suppressor syndromes with increased incidence of central and peripheral nervous system tumors and an autosomal dominant inheritance pattern. It is important to recognize these syndromes in order to provide optimal clinical care and guide genetic counseling for patients and their families. NF1 is caused by pathogenic variants in the NF1 gene, NF2 by pathogenic variants in the NF2 gene, and schwannomatosis by pathogenic variants in SMARCB1 and LZTR1 genes. These disorders have both tumor and non-tumor manifestations but this chapter’s discussion focuses on the oncologic manifestations. NF1 patients are predisposed to neurofibromas, gliomas, pigmented lesions, and bony abnormalities. NF2 patients are predisposed to schwannomas, meningiomas, and ependymomas. SWN predisposes to multiple schwannomas and, less commonly, meningiomas. The neuro-oncologist should understand the genetics, diagnosis, common tumor manifestations, and management of these complex patients.