A giant urinoma in a neonate without obstructive uropathy

We report a neonate with a giant urinoma and renal failure. A 7-day-old boy had a giant abdominal mass of 6.5 cm x 8 cm in the right quadrant, gastroe sophageal reflux, and renal failure caused by the compression from the mass . Radiological observations revealed a multiseptated cyst and neither kidne y could be detected. To relieve these symptoms percutaneous drainage was pe rformed. The contents of the fluid were similar to the patient's urine. The symptoms were improved by the drainage, and we found the left kidney to be absent and the right kidney small. Four prenatal ultrasound scans detected no cystic lesions in his abdomen. Neonatal urinomas are commonly complicat ed by obstructive uropathy, such as posterior urethral valves or ureteropel vic junction obstruction. These obstructive uropathies were ruled out by re trograde pyelography and voiding cystourethrography. A severely dilated upp er pole of a double collecting system was also ruled out by intravenous pye lography and direct observation of the kidney during an open biopsy. The ca use of the urinoma is still uncertain, but trauma during delivery and the d ysplastic right kidney may be involved.