Abdominal aortic aneurysm of unknown origin and renovascular hypertension in a 25 year old male.

A 25 year old male had an abdominal aortic aneurysm involving bilateral renal arteries. Aortography revealed no irregularity in the aortic wall but a slight kinking at the tenth thoracic level followed by a fusiform aneurysm. Computed tomography (CT) showed an enlarged aortic lumen with an intraluminal thrombus. Plasma renin activity (PRA) was markedly increased (11 ng/ml/h), and the administration of captopril caused a further increase in PRA with a significant reduction in blood pressure, indicating the presence of renovascular hypertension. Abdominal aneurysm in a young adult is very rare. The etiology of the aneurysm appears to be idiopathic.