The blood tests are supposed to help diagnose. There is a bunch, your arms will be sore!!! Hormones, liver, CgA protein, total blood test, I cant remember them all. I would trust your endocrinologist and oncologist (if they are two different people) to order them. If you need mine, I can pull them from MyChart. Happy to help. I am a bit of a wrong person to talk about it, my tests were all over the board, my tumor was active episodically, and spiked during surgery. Anesthesiologist told me they had a field day couple of hours into the procedure. I am still here today! Every case is different, these tumors are all unique, just like people who have them.
Just my 25c, sorry its all in pennies :-).
Best of luck.