Immunohistochemistry and morphometric analysis of pelviureteric junction complexes in children with hydronephrosis

Aim: The study aimed to analyze the musculature and innervations of pelviureteric junction (PUJ) complex and upper ureter by morphometry and immunohistochemistry in surgically resected specimens of PUJ obstruction and compares the findings with normal controls. Materials and Methods: Specimens of the PUJ were obtained from twenty patients with hydronephrosis due to PUJ obstruction undergoing surgical treatment in this unit from 2013 to 2015. In the control group, seven PUJ complexes were taken from patients who had nephrectomy due to trauma and Wilms tumor. The sections were stained with H and E stain and elastic von Gieson stain. For immunohistochemistry, the tissue sections were immunostained by an indirect immunoperoxidase method for S-100 and neuron-specific enolase. Results: Histopathologically, the predominant arrangement of muscle fibers was layered, i.e., a thick circular layer surrounded by two longitudinal layers on either side in PUJ of obstruction patients. S-100 immunoreactivity in the muscle layer showed dense neural innervation in PUJ complex of obstructed patients. Conclusions: Circular enhanced musculature may cause a sphincter-like activity with holding up of urine. The higher density of neuronal expression in PUJ might be responsible for causing constant contraction and intrinsic obstruction