Hello from JustAnswer.
Thyroid nodules are fairly common, occurring in about 5-10% of people over their lifetime. They are more common with age, with the average age at detection of 60 years of age. The vast majority of thyroid nodules are benign, but there is a small risk of thyroid cancer. Only about 5% of thyroid nodules are found to be cancer. Size does not indicate a significant risk for malignancy.
Actually. smaller nodules that cannot be felt are much more common, but the above numbers and risk for cancer refers to only to those nodules that ae large enough to be felt by the patient or doctor.
Ultimately, though, the only way to say with certainty whether a specific nodule is cancer is to perform a biopsy. Imaging tests can give suggestions of whether it appears worrisome, but no imaging test can accurately say whether it is cancerous.
I realize that saying that there is a 5% chance of cancer can be anxiety producing in some people, but it is important to also remember that this also means that there is a 95% chance that the nodules will be benign. And even for the worst case scenario that this is thyroid cancer, it is also important to realize that the current treatment for thyroid cancer is excellent with very high cure rates - with >95% cure rates for most thyroid cancers. But as with any cancer, it is better to identify the cancer sooner than later.
So, it is much more likely that these will be found to be benign, but even if found to be cancer, it is a cancer in which there is an excellent prognosis.
If I can provide any additional information, please let me know.