Conservative Management of Segmental Multicystic Dysplastic Kidney in Children

Objective: To assess the clinical characteristics and natural course of segmental multicystic dysplastic kidney (MCDK). Methods: We retrospectively analyzed the medical records of 40 patients (43 renal units) diagnosed as having segmental MCDK between January 2002 and June 2014. Segmental MCDK was classified as typical when it was localized to the upper pole of a duplex collecting system, and otherwise as atypical. We investigated involution, associated anomalies requiring surgery, and complications of segmental MCDK. Results: Of 43 renal units, 23 were typical and 20 were atypical. During 71.5 (interquartile range: 37.5-84.1) months of median follow-up period, complete and partial involution were observed in 48% and 26% of the typical group and 30% and 35% of the atypical group, respectively. In the typical group, involution was complete significantly earlier (P =.048) and ipsilateral anomalies were more frequently observed (P =.002). The initiation point of involution and contralateral anomalies were not different in the two groups. Hypertension developed in 1 case with contralateral MCDK and 1 case with contralateral renal agenesis. Conclusion: Segmental MCDK is not a rare disease entity, and conservative treatment appears to be sufficient with thorough follow-up, including regular monitoring of blood pressure and renal function, and with ultrasonography.