Underpinning pathophysiology of fulminant cerebral edema following CAR T-cell therapy remains not fully elucidated, yet histological and neuroimaging evidence supports cerebral vasogenic edema triggered by cytokine-mediated blood-brain barrier (BBB) dysfunction as the underlying mechanism [[1]-[4]]. The brainstem appears hypo-attenuated compared to other infra-tentorial brain structures Our case illustrates the potentially fatal evolution of neurotoxicity related to CAR T-cells therapy resulting from fulminant cerebral edema. In the RocKet trial, a study evaluating anti-CD19 CAR T-cells in adult patients with B cell acute lymphoblastic leukemia, five patients developed fatal cerebral edema, leading to early termination of the study [[8]]. [Extracted from the article]