[Pathological study of Willis's circle in autopsy cases of polycystic kidney disease].

Two autopsy cases of polycystic kidney disease with intracranial aneurysms were reported. We made a pathological study of their vascular system with special reference to Willis's circle in order to prove the inherent abnormality of vascular system in patients with polycystic kidney disease. A 57-year-old man was revealed to have polycystic kidney disease with left middle cerebral artery aneurysm and aortic stenosis. The other 58-year-old man was revealed to have polycystic kidney disease with cerebral aneurysms both in anterior communicating artery and basilar artery, aortic dissecting aneurysm, cerebral infarction and myocardial infarction. Histologically, both abrupt interruption and partial disappearance of internal elastic lamina are found frequently in the wall of Willis's circle. This abnormality of internal elastic lamina may be attributable to congenital factors and rise the frequency of occurrence of intracranial aneurysms in polycystic kidney disease.