Two infantile cases of primary megaloureter with uncommon pathological findings: ultrastructural study and its clinical implication.

We report 2 cases of primary megaloureter, which might shed an unconventional insight into the etiology of this controversial issue. On histological studies, using light and electron microscopy, the dilated segment was characterized by sparse muscular development with an unrecognized amount of thick myofilaments and interstitial fibrosis, while the distal few centimeters of the narrowed segment maintained relatively normal muscular and interstitial features. The etiological and clinical implication of these findings in the management of primary megaloureter is discussed.