How is thyroid cancer diagnosed?

Many cases of thyroid cancer can be found early. Most early thyroid cancers are found are found by the doctor during a routine checkup. Other thyroid cancers are found when patients ask their doctors about neck lumps or bumps they have noticed.  

If you have symptoms such as a lump or swelling in your neck, you should see your doctor right away. Fortunately most thyroid cancer cases are a slow "growing" cancer known as papillary thyroid cancer. Although it's unusual, some thyroid cancers may not cause symptoms until after they reach an advanced stage.

Although blood tests or thyroid ultrasound often find changes in the thyroid, these tests are not used as screening tests for thyroid cancer unless there is a reason (such as family history) to suspect a person is at a higher risk for thyroid cancer.

People with a family history of medullary thyroid carcinoma (MTC) may be at very high risk for getting this cancer. Most doctors suggest genetic testing for these people when they are young to see if they carry the gene changes linked to MTC. For people who may be at risk but don't get genetic testing, there are blood tests that can help find MTC at an early stage, when it may still be cured. Thyroid ultrasounds may also be done in high-risk people.

If medullary thyroid cancer (MTC) is suspected or if you have a family history of the disease, blood tests of calcitonin levels can help look for MTC. Calcitonin is a hormone that helps control how the body uses calcium. This test is also useful to see if the cancer has come back after treatment. People with MTC often have high blood levels of a protein called carcinoembryonic antigen (CEA). Tests for CEA can sometimes help find this cancer.

Imaging Tests: Imaging tests are methods to make pictures of the inside of your body. They may be done for a number of reasons: to find out whether a suspicious area might be cancer, to learn how far the cancer may have spread, and to help find out if treatment has been working.

Nuclear medicine scans: For nuclear medicine (radionuclide) scans, substances with small amounts of radiation are put into the body. Special cameras are then used to see where the substances go. These tests can help find cells in the body that are not acting normally, although they don't give very detailed images.

Vocal Cord Exam: Thyroid tumors can sometimes affect the vocal cords. If you are going to have surgery to treat thyroid cancer, a vocal cord exam will likely be done ahead of time to see if the vocal cords are moving the way they should. For this exam, the doctor looks at the voice box with special mirrors or with a thin tube with a light and a lens on the end (a laryngoscope).

Last Medical Review: 08/05/2011

Last Revised: 08/05/2011