Infundibular widening of the posterior communicating artery progressing to true aneurysm.
D000328:Adult; D002539:Cerebral Arterial Diseases / Q000150:complications*; D004108:Dilatation, Pathologic / Q000150:complications; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000209:etiology*; D013997:Time Factors