Multicystic renal dysplasia masquerading as ureteropelvic junction obstruction

Multicystic dysplastic kidney usually is identified easily by ultrasound examination, and treatment decisions are based upon the diagnosis and clinical status of the patient. We report on 3 newborns in whom renal ultrasound findings were strikingly similar to severe neonatal ureteropelvic junction obstruction but operation revealed multicystic dysplastic kidney.