[BCG-therapy as a rare reason for postrenal failure].

Area of Science:

• Nephrology
• Urology
• Oncology

Background:

• Bladder cancer treatment often involves Bacillus Calmette-Guérin (BCG) immunotherapy.
• Acute renal failure is a potential complication, though postrenal causes are infrequent.

Observation:

• A patient undergoing BCG therapy for bladder cancer developed acute renal failure.
• Cystoscopy confirmed bilateral intramural narrowing of the distal ureters, consistent with BCG-induced ureteral stenosis.

Findings:

• The patient presented with urinary congestion (Level II-III) secondary to bilateral ureteral stenosis.
• Renal function normalized after the placement of a double-J catheter.

Implications:

• BCG-induced ureteral stenosis should be considered in the differential diagnosis of postrenal failure in patients receiving BCG therapy.
• This case highlights the importance of recognizing rare but serious side effects of immunotherapy.