Other diagnostic studies for thyroid adenoma include thyroid scan, which demonstrates hot, cold, or functioning nodule.

• Nuclear medicine can be used to image the thyroid with radioactive technetium or iodine imaging of the thyroid.^[1]

• Cold
  • 85% of thyroid nodules are cold and 8% of cold and warm thyroid nodules are malignant.^[2]
• Functioning nodules
  • The cells in the nodule take up the iodine much like a normal cell does
  • The likelihood of cancer is very low in these types of nodules and a biopsy is usually not necessary.
• Hot
  • 5% of thyroid nodules are hot. Malignancy is virtually nonexistent in hot nodules.^[3]
• An ¹²³I scan showing a hot nodule, accompanied by a lower than normal thyroid stimulating hormone, is strong evidence that the nodule is not cancerous.