However, they also form the hallmark feature of NF2-SWN, when found bilaterally, and may arise unilaterally in 5% of patients with LZTR1-related schwannomatosis.102,103 Most sporadic VSs harbour somatic mutations in NF2 or genes linked to it.104,105 Unlike meningioma, VS is recognized as one histopathological entity but with dense (Antoni A) and loose cellular (Antoni B) areas. This evidence concerns the gene NF2 and meningioma.