Lecture Code : PN01-S1
Session Name : Pediatric Nephrology
Session Topic : Pediatric Nephrology
Date & Time, Place : June 11 (Thu) / 13:00-14:30 / Room 4 (203), 2F
Multicystic Dysplastic Kidney (MCDK): Natural History and Follow-up Strategies
Minji Park
Kyungpook National University Hospital, Republic of Korea
Multicystic dysplastic kidney (MCDK) is one of the most common congenital renal anomalies detected on prenatal ultrasonography, with an estimated incidence of 1 in 2,200 to 1 in 4,300 live births. It is thought to results from heterogeneous mechanisms, including severe fetal ureteral obstruction or defective interaction between the ureteric bud and metanephric mesenchyme, leading to a non-functioning kidney replaced by multiple non-communicating cysts. While bilateral MCDK is almost uniformly fatal, unilateral MCDK is compatible with a normal life expectancy in the presence of a healthy contralateral kidney.
This lecture provides an evidence-based overview of unilateral MCDK, addressing pathogenesis, diagnostic evaluation, natural history of involution, compensatory hypertrophy of the contralateral kidney, long-term complications, and follow-up strategies.
Available data indicate that complete or partial involution occurs in 60–93% of cases, with variability depending on age at diagnosis and follow-up duration. The role of routine dimercaptosuccinic acid (DMSA) scintigraphy and voiding cystourethrogram (VCUG) remains controversial, with current evidence favoring a selective approach than universal approach. Compensatory hypertrophy of the contralateral kidney is observed in approximately 20-30% of patients at birth and increases to 77-82% during long-term follow-up, representing a key determinant of renal functional reserve. However, the hyperfiltration hypothesis suggests a risk of glomerulosclerosis and associated long-term sequelae, including proteinuria (~10%), hypertension (~7%), and reduced renal function (~8%) in patients with a congenital solitary functional kidney.
The lecture concludes by translating this evidence into a practical, risk-stratified follow-up framework, drawing on current international consensus recommendations to guide surveillance intensity from infancy through the transition to adult care, with the overarching goal of preserving renal function across the lifetime of affected individuals.
Keywords: Multicystic dysplastic kidney (MCDK), Congenital solitary functioning kidney, Compensatory hypertrophy