Pediatric Donut-Shaped Basilar Artery Aneurysm.

Intracranial aneurysms are uncommon in the pediatric population. We present a case of an 11-year-old boy presenting with subarachnoid hemorrhage caused by a "donut-shaped" basilar tip aneurysm. It occurs when the flow geometry produces a circumferential laminar flow into the aneurysmal sac, resulting in a central thrombosis. Optimal management of this type of aneurysm is not already clear, and further studies are needed to clarify the best treatment approach, especially in the pediatric population.