PIK3CA and arteriovenous hemangioma/malformation: Here, we identified a putative new tumor type characterized by the same dural location, a similar histopathological pattern and a frequent GJA4 p.Gly41Cys mutation (3/6 cases), distinct from genes implicated in CCM (CCM1/2/3, MAP3K3, PIK3CA) and arteriovenous malformations (KRAS) of the brain.