“…These fistulae could be secondary to chronic inflammation caused by nonspecific infection (xanthogranulomatous pyelonephritis) or specific infection like in urogenital tuberculosis, radiation therapy, urolithiasis [2,3] or a foreign body [4,5] (ureteral stents, nephrostomy…). Fistulae can also form, resulting of a traumatism [6,7] that can either be blunt or open (stab wounds or ballistic trauma), or a tumoral process involving either the digestive tract [8] (colonic adenocarcinomas…) or the urinary system [10] (renal cell carcinoma, upper tract transitional cell carcinoma). Some cases of iatrogenic fistulae after the placement of a nephrostomy tube have been reported [5].…”