CDKN2A and meningioma: Meningiomas are considered grade 3 when they have 20 or more mitoses in 10 HPF of 0.16 mm2, and/or frank histological anaplasia with a morphology resembling a carcinoma, melanoma, or sarcoma, and/or TERT promoter (pTERT) mutation, and/or CDKN2A/B homozygous deletion (HoDe) [4].