How is Thyroid Cancer Diagnosed?

Thyroid cancers are often found at an early stage. Some early thyroid cancers are found when patients see their doctors because of lumps (or nodules) in their neck. Other times, thyroid cancers are found by doctors during routine checkups or when patients have tests for other health reasons.1

To confirm whether a thyroid nodule is cancerous, your doctor will probably refer you to an endocrinologist. They may use a procedure called an ultrasound guided fine needle aspiration (FNA) biopsy. During this procedure:

  • a small needle is inserted through the skin into the thyroid nodule.
  • The needle draws out a sample of the material, or tissue, inside the nodule.
  • This sample is then examined under a microscope.
  • The cells collected are sent to a pathologist, who will determine if the nodule is cancerous.
  • The pathologist also identifies the type of thyroid cancer if present.

In addition to a biopsy, the endocrinologist may recommend:

  • a blood test to measure the level of thyroid hormone in your body, and
  • thyroid ultrasound or other imaging studies.1-3

Fine needle aspiration of a thyroid nodule

biopsy for thyroid cancer nodule biopsy for thyroid cancer nodule

What if the Nodule is Thyroid Cancer?

Thyroid cancer treatment usually begins with surgery to remove all or half of the thyroid. Regardless of surgical procedure, each case will be followed by long-term monitoring.3 Each of these steps is described in more detail in the Steps in the Treatment of Thyroid Cancer section.


Thyroid Cancer Glossary

My Doctor Discussion Guide

My Doctor Discussion Guide

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Thyrogen® (thyrotropin alfa for injection) 0.9 mg/mL after reconstitution


Diagnostic: Thyrogen is used to help identify thyroid disease by testing the blood for a hormone called thyroglobulin in the follow up of patients with a certain type of thyroid cancer known as well differentiated thyroid cancer. It is used with or without a radiology test using a form of iodine.

Limitations of Use:

The effect of Thyrogen on long term thyroid cancer outcomes has not been determined.

When Thyrogen is used to help detect thyroid cancer, there is still a chance all or parts of the cancer could be missed.

Ablation: Thyrogen is also used to help patients prepare for treatment with a form of iodine to remove leftover thyroid tissue in patients who have had surgery to take out the entire thyroid gland for patients with well differentiated thyroid cancer who do not have signs of thyroid cancer which has spread to other parts of the body.

Limitations of Use:

In a study of people being prepared for treatment with a form of iodine after thyroid surgery, results were similar between those who received Thyrogen and those who stopped taking their thyroid hormone. Researchers do not know if results would be similar over a longer period of time.


There have been reports of events that led to death in patients who not had surgery to have their thyroid gland removed, and in patients with thyroid cancer cells that have spread to other parts of the body.

Patients over 65 years old with large amounts of leftover thyroid tissue after surgery, or with a history of heart disease, should discuss with their physicians the risks and benefits of Thyrogen.

Thyrogen can be administered in the hospital for patients at risk for complications from Thyrogen administration.

Since Thyrogen was first approved for use, there have been reports of central nervous system problems such as stroke in young women who have a higher chance of having a stroke, and weakness on one side of the body.

Patients should remain hydrated prior to treatment with Thyrogen.

Leftover thyroid tissue after surgery and cancer cells that have spread to other parts of the body can quickly grow and become painful after Thyrogen administration.

Patients with cancer cells near their windpipe, in their central nervous system, or in their lungs may need treatment with a glucocorticoid (a medication to help prevent an increase in the size of the cancer cells before using Thyrogen.)


In clinical studies, the most common side effects reported were nausea and headache.


Pregnant patients: Thyrogen should be given to a pregnant woman only if the doctor thinks there is a clear need for it.

Breastfeeding patients: It is not known whether Thyrogen can appear in human milk. Breastfeeding women should discuss the benefits and risks of Thyrogen with their physician.

Children: Safety and effectiveness in young patients (under the age of 18) have not been established.

Elderly: Studies do not show a difference in the safety and effectiveness of Thyrogen between adult patients less than 65 years and those over 65 years of age.

Patients with kidney disease: Thyrogen exits the body much slower in dialysis patients and can lead to longer high TSH levels.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.


  1. American Cancer Society. Can Thyroid Cancer Be Found Early? 2016. https://www.cancer.org/cancer/thyroid-cancer/detection-diagnosis-staging/detection.html. Accessed January 2019.
  2. American Association of Endocrine Surgeons. Thyroid nodule: Fine needle aspiration biopsy (FNA). 2015. http://endocrinediseases.org/thyroid/nodule_fna.shtml. Accessed January 2019.
  3. Haugen BR, Alexander EK, Bible K, et al. 2015 American Thyroid Association (ATA) Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid. 2015; DOI: 10.1089/thy.2015.0020.