Classification of schwannomas and the new naming convention for "neurofibromatosis-2": Genetic updates and international consensus recommendation.

Abstract

Despite their similar nomenclature, Neurofibromatosis type 1 (NF1) and "Neurofibromatosis type 2" are discrete and clinically distinguishable entities. The name of "neurofibromatosis type 2" has been changed to NF2-related schwannomatosis, to reflect the fact that neurofibromas do not occur in this syndrome and therefore the name "Neurofibromatosis" is factually incorrect. Furthermore, multiple schwannomas, a hallmark feature of NF2, can also occur in patients with mutations in genes including SMARCB1 and LZTR1, all exhibiting overlapping clinical features. Current understanding suggests that schwannomatosis (SWN) encompasses a range of clinical presentations consisting of clearly defined, separate subtypes which share a common phenotype of schwannomas. Recognizing these newly emerging subtypes, the International Consensus Group on Neurofibromatosis Diagnostic Criteria (I-NF-DC) proposed a revised nomenclature for NF2 and related disorders in 2022. This review article focuses on this critical update in diagnostic terminology, highlighting the key gene-related SWN subtypes relevant to neuroradiologists. By emphasizing molecular testing alongside clinical features, the revised system facilitates a more precise diagnosis, potentially paving the way for personalized treatment strategies. Additionally, the flexible structure accommodates future discoveries of genes associated with SWN.