Carcinoma in an ileal conduit after bladder reconstruction. Carcinoma developed in an ileal conduit after orthotopic bladder replacement in a 44-year-old man. The patient was a resident of Iowa, United States, in a group of 50 patients with an ileal conduit reconstructed with a Studer modification of the Indiana pouch; 24 of the patients were from Iowa and had been transplanted during the previous six years. Five of seven patients who were transplanted or residents of Iowa had carcinoma develop in the ileal conduits, whereas only one of the three patients transplanted from Iowa who had not been residents of Iowa had carcinoma. The results suggest that there may be some association between early irradiation and the development of this complication.