A PROBABLY FAMILIAL SACCULAR ANEURYSM OF THE ANTERIOR COMMUNICATING ARTERY IN A NEONATE

A 32-day-old boy died of recurring cerebral hemorrhages starting on th e 4th day of life. Autopsy disclosed a remittingly ruptured saccular a neurysm of the anterior communicating artery. A 7-day-old brother of h is had previously died of recurring subarachnoid hemorrhages as well. The young age of the patient, the site of the aneurysm, and its probab ly familial occurrence make this case a unique one. Nonaneurysmatic ba sal cerebral arteries showed remarkable histological changes partly re sembling those seen in fibromuscular dysplasia, some of them probably representing preaneurysmatic alterations. A known underlying systemic disease could not be found, and immunohistochemical detection of type III collagen revealed no identifiable deficiency.