Congential obstructive nephropathy gets complicated

Caliceal diverticulum with ureteropelvic junction obstruction in a dysplastic kidney: a pediatric case report

A caliceal diverticulum is a rare entity in children. Its etiology is closely associated with that of ureteropelvic junction malformations and renal dysplasia. We herein present a case of these complex disorders in an infant. A renal cyst and hydronephrosis were found in the left kidney during the fetal period. The postnatal diagnosis was hydronephrosis due to ureteropelvic junction obstruction and a caliceal diverticulum in the left dysplastic kidney. Although left renal function was severely decreased, the patient had no symptoms. Therefore, we did not perform surgical treatment. At the time of this writing, the patient was 3 years 8 months old and had developed no symptoms.

Morphological and functional analyses of two infants with obstructive renal dysplasia

Renal dysplasia associated with urinary tract obstruction comprises two distinct phenotypes, i.e., multicystic dysplastic kidney (MCDK) and obstructive renal dysplasia (ORD). MCDK is a common manifestation in infants with renal dysplasia, which is characterized by multiloculated thin-walled cysts with no functional parenchyma and an atretic ureter owing to pyelocalyceal occlusion early in fetal life. In contrast, ORD is an extremely rare condition which is caused by severe obstruction of the distal ureter or urethra. Here, we report two infants with ORD. Both patients manifested unilateral kidney enlargement with multiple cortical cysts, mild hydronephrosis, and marked dilatation of the ipsilateral ureter. Contralateral kidneys and urinary tracts revealed no apparent radiological abnormalities. Serial ultrasonographic studies of fetal and neonatal kidneys in both cases revealed that ureteral dilatation was evident at gestational week 16 and 27, respectively, and most of the cortical cysts disappeared within 1-3 months after birth. The functions of the affected kidneys were severely impaired but evident at the time of birth. These manifestations were consistent with a diagnosis of ORD, and were distinct from the features of MCDK. Our observation of fetal and infantile kidneys in these two cases provides us with a better understanding of the pathogenesis of ORD.