Giant aneurysm of the distal posterior inferior cerebellar artery in an 11-month-old child presenting with obstructive hydrocephalus.

Intracranial aneurysms are rare in children although several features distinguish them from adult aneurysms including variation in anatomic distribution and an increased incidence of giant and posterior circulation aneurysms. Subarachnoid hemorrhage is the most frequent presentation; however, clinical presentation suggestive of intracranial tumor is not uncommon making accurate diagnosis difficult. Direct clipping is recommended whenever possible although alternative techniques may sometimes be necessary. This report of a giant aneurysm of the distal posterior inferior cerebellar artery in an 11-month-old child illustrates the occasional difficulty in diagnosis and management of these unusual aneurysms.