Neonate with urinary ascites but no hydronephrosis: unusual presentation of posterior urethral valves

Posterior urethral valves (PUV) are an important cause of paediatric obstructive uropathy. PUV are usually diagnosed by prenatal ultrasonography (US) revealing hydronephrosis and bladder distention. We describe a 17-day-old male infant with abdominal distention who had no hydronephrosis on prenatal US. Laboratory investigations showed serum creatinine of 12 mg/dL, hyperkalaemia and metabolic acidosis. Abdominal US showed large amount of ascites, normal-sized kidneys without hydronephrosis and incompletely distended bladder. Paracentesis revealed clear, yellow ascitic fluid with creatinine level of 27 mg/dL compatible with urinary ascites. Voiding cystourethrogram (VCUG) demonstrated PUV with a dilated posterior urethra, grade 5 right vesicoureteral reflux and a ruptured kidney fornix with peritoneal extravasation of contrast. Foley decompression resulted in normalisation of creatinine within 72 hours. Transurethral resection of PUV was performed, and a repeat VCUG showed recovery of forniceal rupture. This case illustrates an unusual presentation of a potentially life-threatening but treatable cause of urinary tract obstruction.