Sarcomatoid is a rare form of bladder cancer, as you know. My advice would be to go ASAP to a place that sees and treats a wide variety of bladder cancer and has expertise in unusual situations. Examples of such places would include MD Anderson, Sloan-Kettering, Johns-Hopkins, USC, Stanford, and the National Cancer Institute. While radical cystectomy might be the start of treatment, there are new and exciting immunotherapy drugs in research which might be useful in your case. They would only be available in research institutions.
You might wish to contact Dr. Argawal at the National Cancer Institute for advice:
Piyush K. Agarwal, M.D.
Center for Cancer Research
National Cancer Institute
Building 10 - Hatfield CRC, Room 2-5952
Bethesda, MD 20892-1210
Please let us know what happens
Diagnosis 2-08 Small papillary TCC; CIS
BCG; BCG maintenance
Vice-President, American Bladder Cancer Society