NF2 and meningioma: NSB meningiomas more frequently had a high grade than SB tumors.9,56 The differences may be based on genomic subgroups including NF2 mutation in NSB tumors, Hedgehog signaling pathway mutation in midline tumors, and non-NF2 mutation in anterior SB tumors.57 Furthermore, Yoshida et al.58 reported that the origin of the meninges differed by location; specifically, the meninges of the midbrain and hindbrain had a mesoderm origin, whereas the meninges of the forebrain had a neural crest origin.