[Clinical and histological study of 25 cases of hydronephrosis caused by primary stenosis of the pyeloureteral junction].

The authors report 25 cases of primary stenosis of the pyelo-ureteric junction (PUJ) in terms of their clinical and histological features. Based on a semi-quantitative study of the histological modifications, the authors attempt to determine whether these modifications are primary and therefore responsible for the stenosis of the PUJ or wether, on the contrary, these changes are secondary to the stenosis. After studying 25 children and adults, it appears that these histological signs are primary and responsible for the malformation: rarefaction of the muscle layers (24 cases out of 25), fibrosis of the sub-mucosa or intermuscular layer in every case, presence of valvular mucosal folds in every case but one.