Thyroid Nodules

Sometimes you can feel or see a thyroid nodule yourself, or your healthcare provider may discover it during a physical exam. Your provider may also discover a nodule with an imaging test done for another reason.

Even though thyroid nodules are almost always noncancerous (benign), the small chance that it could be cancer means that most thyroid nodules need some type of evaluation.

What tests will be done to diagnose and evaluate thyroid nodules?

Your healthcare provider may order any of the following tests to help diagnose and evaluate a thyroid nodule:

• Thyroid blood test: This test checks the levels of thyroid hormone in your blood. The hormone levels are usually normal even if you have nodules, but they can be abnormal in some cases and point to thyroid disease.
• Thyroid ultrasound: This is an imaging test that uses sound waves to create pictures of your thyroid gland. It can determine if a nodule is solid or a fluid-filled cyst. (The risk of cancer is higher in solid nodules.) This test also checks on the growth of nodules and helps find nodules that are difficult to feel. In addition, providers sometimes use ultrasound to help guide the placement of the needle during a fine-needle biopsy.
• Fine-needle biopsy: With this test, your provider uses a very thin needle to take a sample of cells from one or more thyroid nodules. They then send the samples to a laboratory for evaluation. Most nodules are noncancerous. However, if the test results are inconclusive, your provider may repeat this test. They may also suggest you have surgery to remove the nodules to make an accurate diagnosis.
• Thyroid scan: In this test, you take a small amount of radioactive iodine orally. Your provider will check to see how much of the radioactive iodine the thyroid nodules absorb and how much is absorbed by normal thyroid tissue. This will provide further information about the thyroid nodules, helping your provider determine the likelihood of cancer.