"Bell-shaped ureter," a radiographic sign of antegrade intussusception

A unique case of a hitherto unreported antegrade intussusception of the ureter secondary to a lead pedunculated polypoid transitional cell tumor is presented. Radiological documentation and surgical verification are illustrated. An attempted explanation of the peculiar radiographic appearance proximal to and within the intussusception is given. The potential aid in preoperative recognition of such an entity is proposed.