You are absolutely right....small cell carcinoma of the bladder is found less than 1% of the time. There haven't been a lot of people with this diagnosis here on the Forum. The last "thread" about small cell was
bladdercancersupport.org/forum/7-metastatic-bladder-cancer/44940-small-cell-carcinoma-of-the-bladder-with-bone-mets#52253
If you go to the top of the Forum, there is a link that says "search Forum." If you click on that, you can search for other, older postings.
Be sure that you have checked the box that says "Forum" under the search.
With such a rare diagnosis, you want to be sure that you are being treated at a place that sees LOTS of bladder cancer cases. Where is your urology team located?
Sara Anne