Aneurysm of an aberrant right subclavian artery--computed tomography.

An aneurysm of an aberrant right subclavian artery was diagnosed with computed tomography (CT) in a 77-year-old man with an asymptomatic mediastinal mass at admission. Although CT clearly demonstrated this rare congenital anomaly, further radiologic study or surgery was not attempted because of the patient's advanced age and lack of symptoms.