A retroperitoneal enteric duplication cyst communicating with the right upper ureter in an infant.

We report an extremely rare case of isolated retroperitoneal enteric duplication cyst with gastric mucosa causing haematuria and dysuria by communicating with the urinary system. A 9-month-old male child was admitted to our hospital with persistent haematuria, dysuria and anaemia. Investigations revealed a retroperitoneal cyst abutting the hydronephrotic non-functioning right kidney. At surgery an isolated retroperitoneal cyst communicating with the right pelviureteric junction was found. The kidney and associated cyst were excised. Histology of the cystic lesion revealed an enteric duplication cyst lined by ectopic gastric mucosa. Isolated retroperitoneal enteric duplication cyst communicating with the urinary tract has not been previously reported in the English literature. We propose that acid secretion into the right renal system was the cause of the haematuria-dysuria syndrome which promptly resolved postoperatively.