Hi,
I am not familiar with your mother's form of thyroid cancer, and having stage 4 of anything is very scary. However, I advise you to seek all of the information that you can possibly get your hands on, advocate for your mother by demanding (in a tactful way) information, clear communication, and choices. She deserves it, and you all do. Studies prove that being empowered and having a positive attitude effect recovery in big ways. So does having love and good, possitive energy poured over your mother.
You are certainly on the right track right now with thoughts of getting more and more opinions. You need to go with a surgeon who hears what you are saying, considers your symptoms, concerns and knowledge on the topic. Many doctors do not like the fact that with the advent of Google, we are privy to almost all of the information that they are privy to, with a few discrepancies here and there, and are working on a process of elimination to cure ourselves just as they are.
TELL YOUR DOCTOR that you hear a contradiction in her/his treatment and what other sources are telling you. Insist that you be told what the doctor's thought process is so that you understand what they are trying. Remember that you are a customer and client and your doctor is a person with a specialized skill that they are offering as a paid service--don't get that confused with someone who cares all that much that you get the very, very best care which you yourself would choose.
You ALWAYS have the right and OWE it to your mother to shop at EVERY single hospital for the RIGHT surgeon. And you will feel empowered for doing it, and if you keep your loved ones informed of your mission to do all of this, they will encourage you and congratulate you as you become the best advocate your mother has ever had. Similar to how our mothers care for us in our young, helpless years; except in this situaion your mother can be doing all of these things along side you as she is physically felling up to it.
Here's someting else i've found useful--Send an e-mail out to everyone you possibly know for two things: 1. connections, names, suggestions on healthcare and endocrinologists and surgeons; 2. to ask for them to shower your mother in well wishes, cards, emails, letters, and small things. I've found that people respond to specific requests for certain prayers and well wishes--for instance: "please send my mother messages of strength and hope as we continue to search for the right treatment for her. personalized visits need to be short as she feels very sick and tired much of the time, and yet these visits are what give her strength each day to know she can get better...etc"
Good luck to you, and I send you what good energy I can for healing.
becca