Typical findings of retroperitoneal fibrosis with circumferential soft tissue surrounding the aortic bifurcation, iliac vasculature and distal descending aorta. It typically starts near the bifurcation and ascends. It is helpful to observe the medialization of the ureters which confirms that this is a fibrosing process. The lack of elevation of the aorta or adenoapthy makes lymphoma very unlikely. This could be confirmed with CT-guided biopsy or checking igG4 levels (which if elevated would obviate the need for biopsy, but if negative would not exclude RPF).