Presentation
Right flank pain.
Patient Data
Moderate hydronephrosis of the right kidney due to ureteral obstruction by retroperitoneal soft tissue mass along the rightward aspect of the aorta.
IVC not well seen, either compressed or invaded by mass. Bilateral common iliac DVT.
Few prominent right common iliac lymph nodes.
6 months after treatment
Resolved right hydronephrosis with new moderate right renal atrophy. Mild post inflammatory/infectious thickening of proximal right ureter.
Persistent but decreased size of right periaortic retroperitoneal mass. IVC remains poorly seen and is likely compressed by mass. Resolved common iliac DVT.
Case Discussion
The differential diagnosis for this case would include retroperitoneal fibrosis, lymphoma, IVC leiomyosarcoma, lymphoma, and TB. TB was confirmed with biopsy after the original CT and the patient underwent therapy, with resolved hydronephrosis on 6-month follow up imaging. While not a common diagnosis in the developed world, it should come to mind whenever dealing with an unknown mass or unusual pathology in the developing world.