Cerebral aneurysm associated with an anomalous hyperplastic anterior choroidal artery.

An unruptured internal carotid artery (ICA) aneurysm arising at the origin of a hyperplastic anomalous AchoA was identified together with a second unruptured middle cerebral artery aneurysm during angiography performed to investigate a striatal and intraventricular haemorrhage in a 55-years-old woman. The anomalous hyperplastic AchoA supplied the left temporal and occipital lobes, and the aneurysm arose proximal to its origin. The patient underwent clipping of the aneurysms, and intra-operative observation revealed that several perforating branches arose directly from the ICA between the AchoA and the ICA bifurcation.