Saccular aneurysm of the superior vena cava detected by computed tomography and successfully treated with surgery.

Vascular lesions must be considered in the differential diagnosis of mediastinal masses. Systemic venous aneurysms are an extremely rare cause of dilatation of the mediastinal shadow on plain chest roentgenograms. We describe what we believe to be the 10th case in the literature of a saccular aneurysm of the superior vena cava, which was detected by computed tomography in a 59-year-old woman and was successfully treated with surgery.