[Unusual benign and malignant ureteral stenosis. Causes, therapy and clinical course].

In 652 patients with ureteral stenoses treated in the last 23 years we found 12 (1.8%) patients with rare benign and 5 (0.7%) patients with rare malignant diseases resulting in ureteral stenoses. Causes, clinical symptoms, diagnostic procedures and pathohistological findings are analysed and discussed with emphasis on the pathohistological diagnosis. Operative procedures are demonstrated and long term follow-up studies presented.