Thyroid cancer screening: neck checks, ultrasound and nodules
There is no standard screening test for thyroid cancer, and the USPSTF recommends against screening adults without symptoms with a neck exam or an ultrasound. That advice does not cover people with symptoms or a higher risk, who should talk to their doctor. (NCI)(USPSTF, 2017)(ACS)
Is thyroid cancer screening recommended?
- USPSTF: recommends against screening for thyroid cancer in adults without symptoms (grade D, 2017). It concludes with moderate certainty that the harms outweigh the benefits. (USPSTF, 2017)
- Who it does not cover: people with hoarseness, pain, trouble swallowing or other throat symptoms; people with a lump, swelling or an uneven neck; and people at higher risk because of radiation exposure, an inherited syndrome linked to thyroid cancer, or a parent, brother, sister or child who had thyroid cancer. (USPSTF, 2017)
- NCI: there is no standard or routine screening test, and studies show screening does not lower the chance of dying from thyroid cancer. Thyroid cancer without symptoms may still be found at a routine physical exam, or during surgery or an ultrasound done for another reason. (NCI)
- ACS: no major professional group recommends routine thyroid cancer screening for most people. Most thyroid cancers are found early, when people see a doctor about a lump or swelling in the neck. (ACS)
The tests in question are a doctor feeling the neck (palpation) and an ultrasound of the thyroid. The USPSTF found the evidence too limited to say how accurate either one is as a screening test. (USPSTF, 2017) Where this fits with other cancer checks: cancer screenings by age.
Why not screen everyone: overdiagnosis
Overdiagnosis means finding a cancer that would never have caused symptoms or become life threatening. Biopsies and cancer treatment can then carry serious risks. Screening can also give false positives, which lead to more tests, and false negatives, which can delay care. (NCI)
- United States: the thyroid cancer diagnosis rate rose from 4.9 per 100,000 people in 1975 to 15.3 per 100,000 in 2013, while the death rate stayed at about 0.5 per 100,000. (USPSTF, 2017) The NCI notes that rates leveled off from 2013 to 2016. (NCI)
- South Korea: after organized cancer screening began in 1999, the thyroid cancer diagnosis rate in 2011 was 15 times the 1993 rate, while the death rate stayed stable. The USPSTF calls this the best population evidence of overdiagnosis. (USPSTF, 2017) Regions of Korea with more screening found more papillary thyroid cancers, but screening was not linked to the thyroid cancer death rate. (Ahn, 2016) The Korean rate rose from 6.3 per 100,000 in 1999 to 63.4 in 2012, then fell through 2016. (Oh, 2021)
More on this idea across all screenings: false positives and overdiagnosis.
Who is at higher risk
- Radiation: radiation to the head and neck as a baby or child, or exposure to radioactive fallout. (USPSTF, 2017)(NCI) The risk is higher with larger doses and younger age at treatment. (ACS, risk factors)
- Family history: a parent, brother, sister or child with thyroid cancer, even without a known inherited syndrome. Most people with thyroid cancer have no family history of it. (ACS, risk factors)
- Inherited syndromes: multiple endocrine neoplasia type 2 (MEN2, from changes in the RET gene) and familial medullary thyroid cancer; familial adenomatous polyposis (APC gene); Cowden syndrome (PTEN gene); and Carney complex (PRKAR1A gene). These are not common. (USPSTF, 2017)(ACS, risk factors)
- Other factors: being female (about 3 times more likely than men), being Asian, and a history of goiter (enlarged thyroid). (NCI) The NHS also lists overweight, thyroid conditions such as Hashimoto's disease or nodules, and some earlier cancers. (NHS, causes)
If any of these apply to you, talk with your doctor about whether you should be screened. (ACS) For people with a family history of medullary thyroid cancer, most doctors recommend genetic testing at a very young age, and regular blood tests and thyroid ultrasounds might help find it early in people who have not had genetic testing. (ACS)
What a thyroid nodule on a scan usually means
A thyroid nodule is a lump in the thyroid gland. Nodules are very common, more common in women, and more likely with age, and only a few are cancer. Many are found by chance on a physical exam or on imaging done for another reason. (MedlinePlus) About 5% of women and 1% of men have a nodule that can be felt, while ultrasound finds nodules in 19% to 68% of people. Cancer is found in 7% to 15% of nodules, depending on age, sex, radiation history, family history and other factors. (ATA, 2015)
A nodule is more likely to be cancer if it is hard or stuck to nearby tissue, if you have a family history of thyroid cancer, a change in your voice or past head or neck radiation, if you are younger than 20 or older than 70, or if you are male. (MedlinePlus)
How radiologists sort nodules: the ultrasound report may describe the nodule with the American Thyroid Association (ATA) patterns or with the American College of Radiology TI-RADS levels. Both are used to decide which nodules need a needle biopsy or a follow-up scan. (ATA, 2015)(ACR TI-RADS, 2017)
| ATA pattern | What it looks like on ultrasound | Estimated cancer risk |
|---|---|---|
| Benign | A purely fluid-filled nodule (cyst) with no solid part. | Under 1%. (ATA, 2015) |
| Very low suspicion | A spongy-looking or partly fluid-filled nodule without the features below. | Under 3%. (ATA, 2015) |
| Low suspicion | A solid nodule as bright as or brighter than normal thyroid, or a partly fluid-filled nodule with an off-center solid area, without the warning features. | 5% to 10%. (ATA, 2015) |
| Intermediate suspicion | A darker (hypoechoic) solid nodule with smooth edges and no warning features. | 10% to 20%. (ATA, 2015) |
| High suspicion | A darker solid nodule with one or more warning features: irregular edges, tiny calcium specks, a shape taller than it is wide, or signs of growth outside the thyroid. | More than 70% to 90%. (ATA, 2015) |
The ATA notes that these estimates come from high-volume centers, and the overall risk may be lower because readers can see the same nodule differently. (ATA, 2015)
ACR TI-RADS gives points for what the nodule looks like (what it is made of, how dark it is, its shape, its edges and any bright spots) and adds them up into a level from TR1 to TR5. (Dahal, 2024)
| Total points | TI-RADS level | Name |
|---|---|---|
| 0 to 1 | TR1 | Benign. (Dahal, 2024) |
| 2 | TR2 | Not suspicious. (Dahal, 2024) |
| 3 | TR3 | Mildly suspicious. (Dahal, 2024) |
| 4 to 6 | TR4 | Moderately suspicious. (Dahal, 2024) |
| 7 or more | TR5 | Highly suspicious. (Dahal, 2024) |
- In general: most nodules are benign. (ACR TI-RADS, 2017) For TR1 and TR2 no biopsy is suggested, and for TR3 to TR5 the higher the level, the smaller the size at which a follow-up scan or a needle biopsy is suggested. (Dahal, 2024)
- Tests after a nodule is found: these may include a TSH level and other thyroid blood tests, a thyroid ultrasound, sometimes a thyroid scan, and a fine needle biopsy of the nodule. (MedlinePlus) The NHS says results usually take about 2 weeks. (NHS, tests)
- Thyroid blood tests: what TSH and free T4 show, and who needs them, are on separate pages: thyroid test results and thyroid test: who needs one.
Where they differ:
- Screening people at higher risk: the USPSTF statement does not cover them and makes no call for them, (USPSTF, 2017) the ACS says doctors might recommend screening for some of them, (ACS) and the ATA cannot recommend for or against ultrasound screening of people with familial thyroid cancer, because there is no evidence it lowers illness or death. (ATA, 2015)
- How nodules are sorted: the ATA uses five named patterns with a risk estimate for each, (ATA, 2015) while ACR TI-RADS adds points into five levels. (Dahal, 2024)
- Which ages are most affected: the NCI says thyroid cancer is most often diagnosed at ages 55 to 64, (NCI) the ACS says it is most common in people in their 30s through 60s, (ACS, risk factors) and the NHS says women are more likely to get it in their early 40s and men in their 70s. (NHS, causes)
Signs to report
These are very common and can be caused by many other conditions, and lumps in the thyroid are usually not cancer, but see a doctor if you notice: (NHS)(ACS, symptoms)
- a lump or swelling in the front of the neck, especially one that grows; (NHS)(ACS, symptoms)
- a lump on the side of the neck; (ACS, symptoms)
- a hoarse voice or other voice change that is not getting better; (NHS)(ACS, symptoms)
- trouble swallowing or breathing; (NHS)(ACS, symptoms)
- pain in the front of the neck, sometimes going up to the ears, or a feeling that something is pressing on the neck; (NHS)(ACS, symptoms)
- a constant cough that is not from a cold. (ACS, symptoms)
The NHS says to ask for an urgent appointment if you are having difficulty breathing. (NHS)
Your doctor decides what your result means for you.
This page does not give surgery, medicine or treatment advice. If you have a flagged result, see after an abnormal screening result for questions to ask.
Questions people ask
Should I get a thyroid ultrasound to check for cancer?
Not as a screening test if you have no symptoms and no higher risk. The USPSTF recommends against screening adults without symptoms for thyroid cancer, with a neck exam or an ultrasound (grade D, 2017), because the harms outweigh the benefits. This does not apply if you have a neck lump, hoarseness, trouble swallowing or a higher risk. (USPSTF, 2017)
Why not screen if it finds cancer early?
Screening finds many small thyroid cancers that would never have caused symptoms or become life threatening, which is called overdiagnosis. In the US and in South Korea, more thyroid cancers were diagnosed over time while deaths from thyroid cancer did not rise. (NCI) (USPSTF, 2017)
I have a family history of thyroid cancer. Should I be screened?
Ask your doctor. The USPSTF advice does not cover people with a parent, brother, sister or child who had thyroid cancer, or people with an inherited syndrome. The ACS says doctors might recommend screening for some people at increased risk. If medullary thyroid cancer or MEN2 runs in your family, most doctors recommend genetic testing at a young age. (USPSTF, 2017) (ACS)
A scan found a nodule on my thyroid. Is it cancer?
Usually not. Thyroid nodules are very common, and only a few are cancer. The ATA puts cancer at 7% to 15% of nodules, depending on age, sex, radiation history, family history and other factors. Your doctor uses the ultrasound features and size to decide whether you need a needle biopsy or a follow-up scan. (MedlinePlus) (ATA, 2015)
Does a TSH blood test check for thyroid cancer?
No. There is no standard screening test for thyroid cancer. A TSH blood test measures a hormone that can be a sign of a thyroid problem if it is too high or too low, and it may be one of the first tests after a nodule is found. See our pages on who needs a thyroid test and on thyroid test results. (NCI) (MedlinePlus, TSH) (MedlinePlus)