That's a good question. Thyroid cancer accounts for only 1 percent of cancers in the US, and there are many people walking around with nodules (mostly benign) and don't even know it.
So even though the only way to know for sure it's cancer is to remove it, removing every nodule would mean many unnecessary surgeries (and lots of money for the surgeons I guess).
So, they look at characteristics. If it's cystic/liquid as opposed to solid, that's likely benign. If it's "hot" and uptakes iodine, 95% are benign, and if it's "cold" (doesn't uptake iodine), 85-90% are benign. So the chances are higher that it's benign.
The FNA only takes a portion of cells, but if it's a follicular or hurthle cell neoplasm, it increases likelihood of cancer (though they still don't know), so they remove it. They can sometimes find pappillary in the fna sample (mine did), so the fna, combined with ultrasound, and sometimes uptake scan, and sometimes sudden growths would offer red flags.
The good news is, that most thyroid cancer is so slow growing, that if you wait and watch over time, you are usually not putting a patient in danger.
Hi Reece, what were the symptoms that led your Dr. to check you for cancer? My TSH is low, used to be high as I am hypo but even with lowering my synthroid dose it continues to stay low, at .01. I'm just afraid of finding out I have thyroid cancer.
The major symptom of thyroid cancer is a nodule, not usually any issue with your blood work. Have you found a nodule with an ultrasound? If so, was it 1cm or more?
That's how my thyroid cancer was found, and how most is found, not through the blood but the nodule investigation. And like I said, each nodule has a 95% chance of being nothing to worry about.
No, my Dr. sent for an ultrasound because my TSH is at .01.
Long story short:
April - discovered I'm hypo, TSH is 9, Dr. prescribes 125mcg synthroid (I feel good on this dose, maybe a tad hyper but for the most part good)
May/June - TSH dropped to .02, Dr. prescribes 75mcg, I'm a little sluggish, nowhere near the energy I had on the 125mcg, + I'm very moody!
June/July - Tsh down again to .01. This is why he sent me for the ultrasound, he told me that my TSH should have gone up since my synthroid dosage was lowered.
He felt my throat but he didn't say whether or not he felt anything. When I had the ultrasound done it went very quickly and it didn't appear to me that the tech was focusing on one side more than the other anything so does that mean no nodules?
As Reece said, TSH has nothing to do with thyroid cancer. Your pituitary may just be over-responding to the Synthroid. For an MD who doesn't understand hypothyroidism treatment very well (which includes most MDs, BTW), the low TSH becomes the primary, but inappropriate, focus. If you felt fine on 125 mcgs and your FT4/3 did not exceed about 75% of their ranges, you should have been left on that dose, no matter where your TSH was.
My own TSH has been no higher than .02 for well over 5 years, but my thyroid hormones are not excessive. My MD understands that this is perfectly ok ... That TSH doesn't matter one whit as long as the thyroid hormones aren't too high.
You were hyper from overmedication according to your labs. On that range, FT4 should not exceed about 1.3. Your total T3 is a tad high as well; but it would be better to see what your free T3 was. Total T3 is not as accurate. The MD was correct to lower your dose, but maybe not by as much as he did.
If your hypo signs are returning, you should be allowed to increase to at least 88 mcgs. If it's been longer than 6 weeks since your decreased dose, labs should be done and the dose increased based on where FT4 [F]T3 are now.