How is thyroid cancer diagnosed?
Thyroid cancer is often discovered when a lump, or nodule, forms in the thyroid gland. While most nodules are harmless (benign), it’s important to have them checked by a healthcare professional.
Sometimes, you might find a thyroid nodule yourself during a self-exam. Other times, a nodule is spotted during an ultrasound, CT scan, or other imaging test done for a different reason.
If a nodule is found, your doctor may recommend an ultrasound to get a closer look. Blood tests can also help assess thyroid hormone levels.
Understanding thyroid cancer tests
Penn Medicine specialists use different thyroid tests to diagnose cancer. We start with a physical exam and talk with you about any family history of thyroid cancer.
Our experts may recommend one or more of the following tests.
A thyroid ultrasound is an imaging test that uses high-frequency sound waves to create detailed pictures of your thyroid. It’s the best imaging test to evaluate a nodule’s size, borders, and internal tissues.
Ultrasound can help your care team see:
- Nodules that have features indicating cancer
- Benign nodules (nodules that aren’t cancerous)
- Nodules that are too small to feel
- Whether a nodule is growing or staying the same over time
Using ultrasound, your endocrinologist and radiologist determine whether they need to do more testing of the nodule. Our specialists use the standardized Thyroid Imaging Reporting and Data System (TI-RADS) to assess and assign a score to thyroid nodules.
Every thyroid nodule receives a score of 1 (no evidence of cancer) to 5 (cancer is highly likely), depending on how it looks on ultrasound. We look at the nodule’s edges (margins), consistency, shape, and other features to determine its score.
Using TI-RADS scores, we recommend additional tests only on nodules that pose a risk of cancer. This means you avoid unnecessary tests and can feel more confident about your thyroid health.
Depending on your ultrasound results, we may recommend a thyroid nodule biopsy, the most accurate way to diagnose thyroid cancer. During this procedure, a small sample of cells is taken from a nodule and examined under a microscope.
Our specialists perform a fine needle aspiration (FNA) biopsy, which is minimally invasive. Using ultrasound guidance, a thin needle is inserted into the nodule to collect cells. The entire process is typically quick. A pathologist then examines the sample to determine if cancer is present.
If cancer is confirmed, we may take samples of thyroid cancer cells to learn more about their genetic makeup. Our experts use what they learn about a tumor’s genetic changes to develop a systemic therapy treatment that’s appropriate for your type of thyroid cancer.
Our specialists either inject or have you swallow a small amount of radioactive iodine. Your thyroid gland—and any thyroid cells in your body—absorbs this material and makes cells visible during an imaging test. We may use radioiodine testing to see if thyroid cancer has spread.
Thyroid cancer tests at Penn Medicine
Your care team may order one or more of the following tests when diagnosing thyroid cancer.
Thyroid cancer staging
If you’re diagnosed with thyroid cancer, the next step is determining the cancer’s extent or stage. Staging tells your care team how much cancer is present in your body and helps them choose the best treatment options for you.
Your care team will use the TNM system to stage your thyroid cancer after reviewing your tissue samples and scan results. This system considers three factors:
- Tumor (T): Evaluates the size of the tumor and if it has spread to nearby tissues—T0 means no cancer, while T1 means a small cancer that hasn’t left the thyroid.
- Nodes (N): Determines if the cancer has spread to nearby lymph nodes—N0 means no spread, and N1 means the cancer has spread to the lymph nodes.
- Metastasis (M): Assesses whether the cancer has spread to other parts of the body, like the lungs or bones—M0 means no spread, and M1 means the cancer has spread to other parts of the body.
Experts in thyroid cancer diagnosis
Our thyroid cancer program brings together thyroid experts from across Penn Medicine. We evaluate hundreds of cancerous and benign thyroid nodules each year. When you choose our program for your care, you can expect:
- Skilled providers: Our experienced radiologists have extra education and years of experience in interpreting imaging test results. Our expertise ensures we don’t recommend testing that isn’t needed.
- Rapid results: Penn Medicine thyroid specialists collaborate during thyroid cancer screening and testing to get the answers you need quickly. Pathologists—doctors who examine tissue samples (biopsies)—stay onsite during testing to share immediate preliminary results with your doctor and ensure all necessary testing is done at the time of biopsy.
- Personalized treatment: We take what we learn from your test results and develop the right treatment plan for your specific needs. You can count on our specialists to provide excellent clinical care that supports the best possible treatment outcomes.
Rated “exceptional” by The National Cancer Institute
Penn Medicine’s Abramson Cancer Center is a world leader in cancer research, patient care, and education. Our status as a national leader in cancer care is reflected in our continuous designation as a Comprehensive Cancer Center by the National Cancer Institute (NCI) since 1973, one of 7 such centers in the United States. The ACC is also a member of the National Comprehensive Cancer Network, one of a select few cancer centers in the U.S., that are working to promote equitable access to high-quality, advanced cancer care.