According to the latest (2021) WHO Classification of CNS Tumors, grade 3 should be assigned based on criteria for anaplastic meningiomas, which comprise malignant cytomorphology (anaplasia) that resembles carcinoma, high-grade sarcoma or melanoma; elevated mitotic activity and a TERT promoter mutation, and/or a homozygous CDKN2A and/or CDKN2B deletion (rhabdoid or papillary histology alone is insufficient) (Table 2). This evidence concerns the gene CDKN2B and meningioma.