Aim: To present a case of pyelic fusion anomaly with orthotopic kidneys which is extremely rare. For maximum and only, it was reported twice in the literature. Its diagnosis may be unpredictable and it may predispose to major surgical complications.
Case report: An 8-year-old child was diagnosed to have a retrocaval ureter which was repaired through a flank incision. A striking finding of a cut and retracted tubular structure was noted during ureteral dissection. Postoperative contralateral perinephric urinoma developed and drained percutaneously. Then, two surgical explorations were done on the left kidney without detection of a cause for urinary extravasation. The left ureter was atretic during explorations. Kidney autotransplantation and ileal reconstructions seemed difficult solutions and nephrectomy was the final step.
Discussion: Pyelic fusion anomaly was reported, mainly, in association to renal fusion anomalies like horseshoe and crossed ectopic kidneys. However, it is the first time to report a case of retrocaval ureter in association to pyelic fusion and normally-located and positioned kidneys. Contralateral urinoma after repair of a retrocaval ureter was a striking complication referred to an underlying crossing left-to-right anomalous pathway. This case represented a surgical trap, because it is an extremely rare and unpredictable association of renal anomalies.
Conclusion: Pyelic fusion with orthotopic well-positioned kidneys is an extremely rare renal anomaly. Its association to retrocaval ureter makes it extremely unpredictable, especially, when it is undiagnosed preoperatively.