Histological and Immunohistological Findings in Vesicoureteric and Pelviureteric Junction Obstructions; a Spectrum of the Same Mishap – An Observational Study

Abstract

Background: Vesicoureteric and pelviureteric junction obstructions (VUJOs and PUJOs) are the most common causes of congenital obstructions of the urinary tract, and yet the pathophysiology of these conditions is unclear. This study aimed to compare the histological findings of age-matched VUJO and PUJO cases for wall thickness, fibrosis, and the presence of interstitial cells of Cajal (ICC). Methodology: This was an observational, inter-institutional study done in the period between January 2020 and May 2021. Twelve age-matched cases of VUJO and PUJO were studied to compare histological findings when stained with hematoxylin and eosin, Masson trichrome, and immunohistochemical stains. Results: Results showed that the thickness of the muscle layer was increased in both VUJO and PUJO with no statistically significant difference. Perifascicular fibrosis was significantly more in VUJO as compared to PUJO. ICCs were less than grade 3 in most cases of VUJO and PUJO. Conclusions: The histological findings of VUJO and PUJO showed similarities, with more fibrosis in VUJO. The density of ICCs was less in both upper and lower urinary obstructions. As both conditions are the result of the same mishap – failure of maturation of fetal ureters, there may be a possibility that patients of PUJO can also have VUJO.