Thyroid Cancer Diagnosis

If you are experiencing symptoms that suggest thyroid cancer, such as a lump on or near your thyroid with or without swollen lymph nodes in your neck, your doctor will most likely run some tests to find out whether the symptoms are related to cancer or some condition. In addition to asking you about your personal and family medical history, you may have one or more of the following tests:

  • Physical exam: Your doctor will feel your thyroid for lumps (nodules) and also check your neck and nearby lymph nodes for growths or swelling.
  • Blood tests: Your doctor may check for abnormal levels of thyroid-stimulating hormone (TSH) in the blood, which indicates that the thyroid is not working well. If your doctor thinks you may have medullary thyroid cancer, you may be checked for a high level of calcitonin and have other blood tests.
  • Ultrasound: An ultrasound device uses high-frequency sound waves to produce images of structures within your body, such as the thyroid. The picture can show the size and shape of the thyroid nodule(s) and whether the nodules are solid or filled with fluid. Nodules that are filled with fluid are usually not cancer. Nodules that are solid may be cancer.
  • Thyroid scan: In a thyroid scan, you swallow a small amount of a radioactive substance (tracer), which is absorbed by thyroid cells. This makes the cells appear on the screen so it can be viewed by your doctor. Nodules that take up more of the substance than the thyroid tissue around them are called “hot” nodules. Hot nodules are usually not cancer. Nodules that take up less substance than the thyroid tissue around them are called “cold” nodules. Cold nodules may be cancer.
  • Biopsy: A biopsy is the only sure way to diagnose thyroid cancer. A pathologist checks a sample of tissue for cancer cells with a microscope. Your doctor may take tissue for a biopsy in one of two ways:
    • Fine-needle aspiration: Your doctor removes a sample of tissue from a thyroid nodule with a thin needle.
    • Surgical biopsy: Your surgeon removes the whole nodule during an operation. If the doctor suspects follicular thyroid cancer, surgical biopsy may be needed for diagnosis.