Bilateral ureteral complete obstruction with huge spontaneous urinoma formation in a patient with advanced bladder cancer.

Spontaneous rupture of the collecting system with extravasation of urine and urinoma formation is usually associated with urinary tract obstruction by a ureteral calculus. Tumor growth is an extremely rare cause of urinary extravasation. Here we report a case of bilateral obstructive uropathy with a huge spontaneous left retroperitoneal urinoma caused by advanced infiltrative transitional cell carcinoma of the urinary bladder. The point of leakage was located in the left renal pelvis. The urinary leakage ceased after percutaneous nephrostomy drainage, and the patient subsequently underwent radical cystoprostatectomy. Histopathology revealed a high-grade urothelial carcinoma of the urinary bladder with pelvic lymph node metastasis. The patient refused any adjuvant treatment and expired 6 months after the operation from disseminated metastasis from bladder cancer.