Thyroid Cancer Diagnosis

Endocrinology Chief James Fagin

Thyroid tumors are found and diagnosed in a number of ways.

Some people notice thyroid cancer symptoms, such as a swelling or a small nodule (called a thyroid nodule) in the front of the neck, and ask their doctor for an examination. But many people have no symptoms. If you’re worried about having thyroid cancer, talk to your doctor about an evaluation.

Steps to a Thyroid Cancer Diagnosis

During your first appointment at MSK, we’ll do a physical examination. We’ll check for any unusual growths or swelling in your:

  • thyroid gland
  • throat
  • vocal cords
  • lymph nodes

We’ll also review any tests you’ve already had done.

Several commercial tests used to diagnose thyroid cancer around the world today are based on discoveries made at Memorial Sloan Kettering.

An ultrasound (using sound waves) of your neck helps us figure out whether we should look at a thyroid nodule more closely in the form of a biopsy. We may also recommend that you get imaging tests — such as a CT, MRI, or PET scan — to get a better look at a thyroid nodule.

Thyroid Biopsy

To do a biopsy, we remove a small sample of tissue from the area to examine under a microscope. This test helps us figure out if a thyroid nodule is benign (noncancerous) or malignant (cancerous).

We use two types of biopsies to diagnose thyroid cancer.

  • Fine needle aspiration can be done in a doctor’s office or by a radiologist. Ultrasound helps us guide a very thin needle into the thyroid nodule to remove a small number of cells.
  • Core biopsy is done for thyroid cancer that has spread (metastasized) outside the thyroid gland or is more advanced. This approach involves using a larger needle.

One of our expert pathologists analyzes the retrieved cells under a microscope to see if cancer cells are there, and what type of cancer cells they are.

What Is Molecular Testing for Thyroid Cancer?

When needed, we use molecular testing of tissue from a thyroid nodule to see if cancer cells are there.

  • DNA approach: This type of molecular test looks for a few specific DNA mutations in the tissue that have been linked to thyroid cancer.
  • Gene classifier: This type of molecular test doesn’t look at specific mutations. Instead, it concentrates more on how various genes linked to thyroid cancer are expressed.

Blood Tests

Blood tests can help us figure out if the thyroid gland is working normally.

  • If your TSH level is low, a thyroid stimulating hormone (TSH) test for follicular thyroid cancer can indicate if there is a thyroid nodule making high levels of thyroid hormone.
  • The level of the hormone calcitonin in the blood is important to test for evaluating medullary thyroid carcinoma (MTC). Our Hereditary Cancer & Genetics program offers information about how to get tested for MTC, which we recommend to children and siblings of people with this type of thyroid cancer.

Risk Levels for Thyroid Cancer

We use information from the diagnosis of thyroid cancer to determine the cancer’s risk level. The risk level reflects in part how likely it is that the cancer will spread beyond the thyroid gland.

What Is Low-Risk Thyroid Cancer?

Thyroid cancer is called low-risk if it is small and still within the thyroid gland (meaning it hasn’t spread beyond the thyroid). Most patients are between age of 20 and 45.

What Is High-Risk Thyroid Cancer?

Thyroid cancer is called high-risk if the disease has spread beyond the thyroid gland or if it grows quickly. Most patients are over age 45.

Our doctors offer treatment options to you based on whether your disease is low-risk or high-risk.