Ureteropelvic junction obstruction in the adult

Cases of ureteropelvic (UP) obstruction presenting for the first time in the adult were analyzed and etiologic factors considered. Besides idiopathic causes, calculi and neoplasm were found in our series. Comparison with other reports of UP obstruction in pediatric patients revealed differences pertaining to mode of clinical presentation, sex predominance and incidence of neoplasm occuring at the UP junction in the adult.