# Unilateral Multicystic Dysplastic Kidney in an Infant: A Case Report of Surgical Nephrectomy, Diagnostic Imaging, and Long-Term Outcomes

## TL;DR

A female infant with a nonfunctioning left kidney due to MCDK showed reduced kidney function and metabolic issues over four years, highlighting the need for close monitoring.

## Contribution

This case emphasizes the importance of proactive biochemical surveillance and early intervention in children with congenital solitary kidneys.

## Key findings

- The infant's right kidney showed hypertrophy but persistently reduced GFR and proteinuria.
- Prenatal metabolic factors like maternal GDM may influence kidney development.
- Early detection of biochemical markers may help prevent chronic kidney disease.

## Abstract

Multicystic dysplastic kidney (MCDK) is a common congenital renal anomaly often considered benign when unilateral and managed conservatively. We report a female infant diagnosed antenatally with left-sided MCDK in the setting of maternal gestational diabetes mellitus (GDM). Postnatal imaging confirmed a nonfunctioning left kidney and a structurally normal right kidney with reduced glomerular filtration rate (GFR) of 49.7 mL/min/1.73 m². Laparoscopic nephrectomy at six months revealed complete parenchymal replacement by cysts with focal cartilaginous metaplasia. Over four years of follow-up, the right kidney demonstrated progressive hypertrophy, yet biochemical surveillance showed persistently reduced GFR (52 mL/min/1.73 m²), proteinuria (0.32 g/L), hyperphosphatemia (4.68 mg/dL), and elevated alkaline phosphatase (197 U/L). This case highlights the discordance between structural compensation and functional sufficiency in solitary kidney physiology, the potential influence of prenatal metabolic factors on nephrogenesis, and the importance of proactive biochemical surveillance. Early detection of proteinuria and phosphate retention, combined with timely nephroprotective interventions, may help mitigate the long-term risk of chronic kidney disease in children with congenital solitary kidneys.