As you have discovered, this is not a common type of bladder cancer. My advice would be to contact centers that treat a LOT of bladder cancer and have specific experience in this disease such as Memorial Sloan Kettering, MD Anderson, Johns Hopkins, USC, and Stanford. You really need to find a place that treats many patients such as yourself.
You can use the Search function at the top right of this page to see what has been previously posted on the Forum about small cell bladder cancer.
Sara Anne