Thyroid Cancer Diagnosis

Accurate diagnosis can be very important to your treatment. At Banner MD Anderson, our experts are among the most experienced and skilled in recognizing and staging thyroid disease.

If you have symptoms that may signal thyroid cancer, your doctor will examine your neck and throat, feeling for lumps or swelling. Your doctor will also complete a medical history. This involves asking questions about your symptoms, other health problems and health problems in other members of your family. If anyone in your family has had thyroid cancer or parathyroid or adrenal tumors, be sure to tell your doctor.

One or more of the following thyroid cancer tests may be used to find out if you have cancer and if it has spread. These tests also may be used to find out if treatment is working.

Fine-needle aspiration biopsy (FNA): A thyroid cancer biopsy (removal of a small number of cells and looking at them under a microscope) is the only way to tell for sure if you have thyroid cancer. In FNA, a thin needle is inserted into the nodule, and cells are taken out to biopsy. Most thyroid nodules are proved by FNA to be benign (not cancer). If the FNA is inconclusive (not showing clearly if the nodule is cancerous), more testing may be needed.

Imaging tests, which may include:

  • Ultrasound
  • CT or CAT (computed axial tomography) scans
  • MRI (magnetic resonance imaging) scans
  • PET (positron emission tomography) scans

Radioactive thyroid scan: If a nodule is papillary or follicular cancer, a radioactive thyroid scan may be used after thyroid surgery to determine if cancer remains or has spread to other parts of the body. Medullary thyroid cancer cells don't absorb iodine, so this test is not useful in this type of thyroid cancer.

Blood Tests for Thyroid Cancer Diagnosis

Genetic testing: If you have medullary thyroid cancer, you will be given a blood test to determine if you carry a gene that sometimes causes this cancer. If the test is positive, your children and parents should be tested to see if they have the gene or thyroid cancer. More than 90% of people who have the gene will eventually develop thyroid cancer.

If your child has the gene, the doctor probably will suggest removal of the thyroid. Although children rarely develop cancer before 5 years old, one type of MTC known as MEN-2B can develop in the early months of life. If the thyroid is removed, then that person will take daily thyroid medication for the rest of his or her life.

If your thyroid cancer test leads to a differential diagnosis, further testing may be recommended.