NF2 and skull base meningioma: Additionally, 4/6 (67%) of the sporadic meningioma were non-skull base (n = 3 convexity, and n = 1 parasagittal) and therefore were more likely to harbour NF2 pathogenic variants than the two skull-base meningioma (n = 2 middle or posterior cranial fossa) [4, 10, 52].