3. Timeline of Events

-July/August 2023: Patient presented with cramping abdominal pain. Imaging on CT revealed hydroureteronephrosis without evidence of ureteric stones.-September 2023: Cystoscopy with retrograde pyelogram revealed left ureteral stricture in the distal/middle segments. Dilation occurred with a balloon, and a stent was placed. Later that month, the stent was removed due to severe discomfort.-October 2023: Nephrostomy tube placed while the stent was removed. MAG3 with nephrostomy 44% with T1/2 > 30 min.-December 2023: Antegrade nephrostogram demonstrated an obliterated ureteral stricture at the level of the pelvic brim. Gastrointestinal/gynecologic malignancy work‐up was unremarkable, with imaging showing no cause of extraluminal ureteric obstruction.-January 2024: Uncomplicated left‐sided ureteral reimplant with pathological findings of ureteral lymphoma (low‐grade B‐cell lymphoma/extranodal marginal zone lymphoma)-February 2024: Patient treated at an outside hospital for further oncologic management