Development of aneurysm from infundibulum of posterior communicating artery with documentation of prior hemorrhage.

The c linica l significance of infundibular widening (junctional dilatation) of the origin of an intracranial artery has been a topic of debate; junc tional dilatation is considered preaneurysmal by some investigators and a normal variant by others. Aneurysm form ation or hemorrhage from an infundibulum rarely has been reported. A pati ent is reported in whom both aneu rysm development at the infundibulum and bleeding from thi s site are documented. This experi ence suggests the possible value of repeat de layed angiography when on ly junc ti onal dilatation is identified in the face of unexplained subarachnoid hemorrhage .