C-kit positive interstitial cells of Cajal network in primary obstructive megaureter.

Recent reports have shown an altered density of interstitial cells of Cajal (ICCs) and peripherin immunoreactive nerve fibres in uretopelvic junction obstruction. The aim was to investigate ICCs immunoexpression and ureteral innervation in primary obstructive megaureter (POM).Eight specimens of POM were obtained during tailoring. Restricted segments of ureters were divided from dilated segments. C-kit and peripherin immunohistochemistry were performed.A normal distribution of ICCs was observed in both the circular and longitudinal muscle layers of the dilated segments. Marked muscle hypoplasia and sparse or no ICCs occurred in the longitudinal muscle layer of the restricted ureteral segments. A normal distribution of peripherin positive fibres was present in both the dilated and restricted segments.Our data confirm defective muscularization in restricted aperistaltic POM. The lack of ICCs in the longitudinal muscular layer is probably due to the absence of c-kit positive muscle embryological precursors. No alteration in the peripherin immunoreactive nerve fibres network was observed in either the dilated or the restricted ureteral segments.