[A case of renal artery aneurysm with calcification].

We report a case of left renal artery aneurysm with ring-like calcification in a 57-year-old man. The selective renal arteriography showed a 30 x 28 mm saccular type aneurysm arising from the periphery of the bifurcation of posterior segment artery. There were no clinical symptoms, such as hypertension and loin pain, but we performed aneurysmectomy for fear of rupture. Histopathological findings showed atherosclerotic changes with marked calcification of wall lacking natural collagen fibers. Renal artery aneurysm with calcification seldom ruptures because of its generally hard wall. However, as cases of rupture through weakness of calcification have been reported, we recommend positive surgical treatment.