Different distribution of c-kit positive interstitial cells of Cajal-like in children's urinary bladders.

We describe the presence of c-kit positive interstitial cells of Cajal-like (ICCs-like) in the walls of the urinary bladders of children. An immunohistochemical study of specimens, obtained at autopsy from either the trigonum (Group A) or the corpus (Group B), was performed using antibodies against c-kit (CD 117). Histological morphometry of the immunoexpression of c-kit positive ICCs-like was performed by means of image analysis system. The c-kit positive ICCs-like were identified by their morphology and counted in the vesical muscle layer in ten adjacent high power fields, each of 0.0479 mm(2). The areas of the epithelial and subepithelial layers containing c-kit positive mast cells (rounded body with no dendritic processes) were neglected. The results were expressed as the number of ICCs-like cells per mm(2). Differences between groups were tested using unpaired Student's t-test preceded by evaluation of normality and Levene's test. Results were considered statistically significant if p 〈 0.05. In Group A, the mean number of ICCs-like cells was statistically significantly higher (41.5 cells/mm(2)) than in Group B (30.4 cells/mm(2)), p 〈 0.05. ICCs-like cells were found within the smooth muscle layer of the urinary bladder. There was a different distribution of these cells in particular parts of the bladder, which was probably due to the different roles of the trigonum and the corpus in the bladders of children.