Congenital saccular aneurysm in a 19-day-old neonate: case report and review of the literature.

A 19-day-old neonate presented with a massive intracranial hemorrhage which was found at autopsy to be due to a ruptured intracranial saccular aneurysm. Detailed histologic evaluation revealed that this was a true congenital lesion. A survey of the literature yielded 19 cases of saccular aneurysm in the first year of life. Together with this report, nine cases are now on record, containing sufficient histologic detail to suggest a congenital basis, contrary to the assertion casting doubt on the existence of the entity. Attention is drawn to the practical importance of recognizing this lesion as a rare cause of intracranial hemorrhage in the neonate, since successful surgical intervention has been reported in several cases.