Neuroendocrine tumor causing ureteral obstruction in a patient with prior ileal conduit.

Acquired hydronephrosis following cystectomy and ileal conduit urinary diversion for bladder cancer is most commonly caused by stricture of the ureter or the ureteroenteric anastomosis. Nevertheless, malignant obstruction due to ureteral tumor recurrence must be ruled out. Neuroendocrine tumors of the ureter are extremely rare and an unlikely cause of hydronephrosis in this setting. We present the first reported case of a patient with a history of bladder cancer and an ileal conduit presenting with hydronephrosis secondary to an obstructing carcinoid tumor of the ureter.