Multicystic kidney. A clinical and histological study of 13 patients.

Multicystic kidney (MK) was diagnosed in 13 patients at the University Central Hospital of Oulu during the 9 year period 1970--78. In the district of the hospital the evaluated incidence of MK was 0.3 per 1000 live-born children. 12 of the patients were infants aged under one year. Two of these died soon after birth; one had severe extraurinary anomalies and the other had bilateral MK. The removal of MK was performed in ten cases. In ten operated and two autopsied patients the cystic dysplasia involved the kidney entirely. There was no discernible normal renal parenchyma and the ipsilateral ureter was always abnormal. On the opposite side one patient had a severe ureteric stenosis with hydronephrosis, and 4 patients had vesicoureteral reflux. Extraurinary anomalies were also common. Three patients had a significant cardiovascular abnormality. The accurate diagnosis could usually be obtained preoperatively. It was found that typical findings of physical examination, plain films, intravenous urography and B-mode ultrasound give sufficient information for accurate diagnosis to be made in most cases. Mictiocystography and endoscopy were required for associated urinary anomalies. Following the diagnosis, the removal of MK should be performed at the correct time, and also if asymptomatic, because these can become symptomatic later in life.