LAUSR

Introduction: The etiopathogenesis of pelviureteric junction obstruction (PUJO) has been debated. Recently, the role of interstitial cells of Cajal-like cells (ICC-LC) has been studied and reported to be the cause of this functional obstruction. We studied the histopathology and ICC-LC density at PUJ and compared it with that of PUJ of the control group and distal ureteric margin of the study group. Methods: A prospective study was conducted which included PUJO patients in the study group and the renal tumor patients in the control group. Histopathological examination (muscle hypertrophy and fibrosis) and immunohistochemistry (ICC-LC density) were done. The muscle hypertrophy, fibrosis, and ICC-LC density at the PUJ in both the groups were compared. A similar comparison was performed between the findings at the PUJ and the distal margin in the study group. Results: The study and control groups included 37 PUJO patients and 13 Wilms tumor patients. The ICC-LC density at PUJ in the study group was significantly lower than that in the control group (P < 0.001) and that at the distal resected margin of the study group (P < 0.001). Significantly increased muscle hypertrophy (P < 0.001) and fibrosis (P = 0.002) were seen at PUJ in the study group compared to the control group. No significant association was noted between the ICC-LC density and muscle hypertrophy at PUJ and the distal resected margin in the study group. Conclusion: A significant decrease in the density of ICC-LC and increased fibrosis and muscle hypertrophy at PUJ in children with PUJO play a role in the etiopathogenesis of the disease.