Multicystic dysplastic kidney (MCDK) in the neonate: The role of the urologist.

I. Background: The urological management of multicystic dysplastic kidneys (MCDK) in the paediatric patient is controversial. Historically, MCDK was rare, presenting with a palpable mass or symptoms, and was managed with open nephrectomy. Wilms’ Tumour was listed on the differential diagnosis. Introduction of antenatal ultrasound (US) transformed MCDK into a common condition which is generally asymptomatic at presentation. Observation through a MCDK registry established that the low risk of WT developing in these kidneys did not justify nephrectomy, and that observation with periodic ultrasound was safe. However, a cost-effective protocol for follow-up was never established. With widespread adoption of paediatric laparoscopy, there is potential for the pendulum to swing back to surgical management of this condition. However, the current indications cited for surgical intervention are more to relieve the iatrogenic symptoms caused by long-term observation, those being parental anxiety and cost to the health care system, than for any confirmed medical indication.