It sounds like you have been through a lot! I am not sure I understand the situation based on what my understanding is of how thyroid cancer grows.
I was told that the only way to definitely diagnose thyroid cancer was by surgery but since it is a slow growing cancer you can wait to see if something grows….if it doesn’t, then it would be less likely that it is cancer.
I just don’t think a doctor can state that something that has not shown up on any scans so far, will metastasize into another part of your body….this does not make sense to me (however it might be something I never heard of before.) Blood tests, ultra sounds and Ct scans seem to be good ways to monitor, but unless they have something specific, I don’t understand why anyone would consider surgery to remove their thyroid.
A lot of doctors seem to recommend second opinions from people in their practice or friends they work with so it might not be neutral. Surgery will give the doctor the ability to know if you have thyroid cancer, however from what I understand it is usually a self contained cancer that doesn’t spread outside the thyroid. If your tests have shown a “normal thyroid,” I don’t understand why you would need to have surgery.