Vascular Pathology: Vascular Disease: Two Specimens of the Circle of Willis Showing Berry Aneurysms
The upper specimen is from a 43 year old woman who died of a subarachnoid haemorrhage. It shows an aneurysm measuring some 20-25 mm in diameter, which bulges from the angle of bifurcation of the basilar artery into the interpeduncular fossa. The lower specimen is an incidental finding from the autopsy of a 68 year old woman who died of myocardial infarction. The circle of Willis shows atheroma, at the junction of the internal carotid and posterior communicating arteries there is a small aneurysmal dilatation filled with clot.