Histological and Histochemical Study of the Vesicoureteric Junction in Infancy and Childhood

Summary The morphology of the vesicoureteric junction was compared using 19 post mortem specimens obtained from male and female Afro‐American and Caucasian children with an age range of 1 to 72 months (mean 4). All specimens were serially sectioned and the tissues processed using standard histological and histochemical techniques (acetylcholinesterase (AChE) and pseudocholinesterase (PChE)). The results failed to reveal any differences in the structure of the vesicoureteric junction with respect to age, sex and ethnic origins. The vesicoureteric junction comprised 3 histologically and histochemically distinct smooth muscle components. Ureteric muscle formed a complete inner layer rich in PChE which continued beyond the ureteric orifices to merge distally with the superficial trigone. An intermediate layer of muscle was also demonstrated whose constituent muscle cells possessed specific histological features and which was rich in both AChE and PChE, which is distinct from that derived from the ureter and detrusor. The presence of detrusor muscle on the outer aspect of the juxtavesical segment of ureter rich in AChE was also confirmed. While this study, using histochemical studies in infants and children, did not reveal any differences in the structure of the vesicoureteric junction with respect to age, sex or ethnic origin, an intermediate layer of muscle was identified with histochemical characteristics more like that of the male genital tract than that derived from the ureter or detrusor muscle.