How is thyroid cancer diagnosed?

One or more of the following tests help to diagnose thyroid cancer:

  • Physical exam: A physical exam can check for lumps or swelling in the neck, enlargement of the thyroid (goiter), and general health.
  • Blood tests: Blood tests check for levels of hormones released by other organs in the body.
  • Thyroid scan: A special camera and radioactive iodine (given as a pill) produce an image of the thyroid on a computer screen. This test is not ordered very often since it is only useful in certain cases.
  • Other scans/imaging tests (CT scan, radioiodine scan, PET scan, MRI): These tests use various methods to determine where the thyroid cancer is, how large it is, and how far it has spread.
  • Fine-needle aspiration (FNA) biopsy: During this procedure, a thin needle is inserted through the skin and into the thyroid gland and/or nodules. A sample of cells is removed and checked for cancer.
  • Ultrasound of the thyroid: This test determines the size of the lump on the thyroid. It is also used to guide a FNA biopsy.
  • Surgical biopsy: Since individual nodules cannot be removed, surgery is done to take out either one thyroid lobe (one side) or the whole thyroid.
  • Genetic testing: A genetic test is a blood test that looks at a person’s DNA, or genetic information.

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