Figure 1a. (a) Unenhanced abdominal CT scan demonstrates a 6 x 6-cm soft-tissue mass adjacent to the aorta, just superior to the bifurcation. Note the small focus of peripheral calcification (arrow). (b) Contrast-enhanced arterial phase CT scan demonstrates prompt peripheral enhancement with central nonenhancement. Note the thin slip of enhancing tissue just anterior to the aortic wall (arrow); this tissue is not readily distinguishable from the aorta.