Prenatal diagnosis of multicystic dysplastic kidney disease in the second trimester screening.

OBJECTIVE: Multicystic dysplastic kidney (MCDK) is the most common antenatally diagnosed cystic renal pathology. It refers to the presence of multiple kidney cysts surrounded by dysplastic parenchymal tissue. The typical MCDK ultrasound finding shows multiple nonconnecting thin-walled cysts within an irregularly outlined kidney. We want to present our own cases as an addition to the relatively scarce literature about MCDK.

METHOD: We retrospectively review 54 cases (21 bilateral and 33 unilateral) with antenatally diagnosed MCDK between the years 1998 and 2012. We compare our data with the published literature and discuss different parameters.

RESULTS: Our findings show a male predominance of 1.8 : 1 and a left side/right side ratio of 0.73 : 1. Most of the cases were isolated findings, but 20.3% were associated with anomalies. One case was a Goldenhar syndrome. Of the bilateral MCDK cases, 14.3% had chromosomal defects. The mean gestational age at time of diagnosis was 20-21 weeks. Renal length was above the 90th normal percentile in 96.2% of the cases.

CONCLUSION: Isolated unilateral MCDK has good prognosis. Bad prognosis is linked to association with other anomalies as well as to bilateral MCDK.