Carcinosarcoma in a bladder diverticulum

A 47-year-old man presented with hematuria and dysuria. He was found to have a carcinosarcoma originating from a bladder diverticulum. He underwent a partial cystectomy and received postoperative chemotherapy. One year later, he presented with a large local recurrence and died shortly afterward. We believe this to be the second case of a carcinosarcoma originating in a bladder diverticulum.