PIK3CA and meningioma: The authors suggest that meningiomas with 22q deletion, 18q deletion, NF2 mutation, and MO or SUFU mutation should be followed annually for 5 years, cases with 1p deletion, 14q deletion, AKT1 or PIK3CA mutation, H3K27me3-negative meningiomas, and TIMP3 or TP73p methylation-positive meningiomas should be followed every 6 months for 5 years, meningiomas with pTERT mutations should be followed every 3 to 6 months indefinitely, and meningiomas with CDKN2A/B HDs should be followed every 6 months indefinitely [168].