[Cystic pyeloureteritis. Presentation of 10 cases]

Based on the analysis of 10 cases of cystic pyeloureteritis, a rare entity of benign outcome, the authors suggest that the cysts might be the result of an hyperreactivity of the urothelium to an aggression, and feel that the correction of the etiologic factors might prevent the evolution of Von Brunn's nests.