1985 Volume 76 Issue 8 Pages 1179-1186
Renal dysplasia designates abnormal development of the ureteric bud and metanephric blastema. Renal dysplasia is regarded as a group of malformations associated with urinary tract anomalies.
The purpose of this report was to make clinicopathological study of 40 renal dysplasias which were operated on in the past 12 years.
This anomaly was found 3 times more commonly in females than in males. Children under 5-years accouted for 65%. All kidneys were associated with urinary tract anomalies: ureterocele 18, ectopic ureter 15, ureteral atresia 5, VUR 1 and posterior urethral valve 1. The ureteral orifice of the dysplastic kidney was normal in 6, medially ectopic in 32 and laterally ectopic in 2. One kidney revealed some uptake on renal scintigraphy and 4 kidneys opacified on enhanced CT, but the other kidneys appeared to be nonfunctioning. The incidence of the abnormalities of contralateral kidneys or urinary tracts was 43%.
Histological criteria of the dysplastic kidney was based on the persistence of primitive duct, in which the columnar epithelium remains undifferentiated and around which the connective tissue becomes fibromuscular collar. Other dysplastic structures, such like primitive tubule, metaplastic cartilage, cysts of various sizes and abnormal glomeruli, were also observed but not uniform in amount or distribution on each specimen.
In general the conservative plastic surgery of the urinary tracts leaves intractable infection because of the small urine volume excreted by the dysplastic kidneys and abnormal ureteric musculature. Every efforts must be taken to seek out contralateral abnormalities before the surgical removal of the kidney or renal segment.
