Table of ContentsView AllTable of ContentsCharacteristicsSymptomsCausesCancer RiskDiagnosisMonitoring and Treatment
Table of ContentsView All
View All
Table of Contents
Characteristics
Symptoms
Causes
Cancer Risk
Diagnosis
Monitoring and Treatment
A thyroid colloid cyst (TCC) is a common, noncancerousnodule in the thyroid glandthat is filled with colloid, a stored form of thyroid hormone.
Many thyroid colloid cysts do not require treatment, but follow-up exams can monitor for any growth or changes. In some cases, surgical removal may be recommended.
This articles reviews the symptoms and causes of thyroid colloid cysts, as well as how they are diagnosed and treated.
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Thyroid Colloid Cysts and Other Nodules
Thyroid colloid cysts are just one type of thyroid nodule—a small growth that forms inside the thyroid gland. Thyroid nodules are very common. About 60% of adults have at least one. Fortunately, about 95% of these are noncancerous.
A thyroid nodule is not always filled with fluid. But when it is, as is the case with thyroid colloid cysts, it is considered cystic.
Colloid nodules may be completely fluid-filled or partially-fluid filled with some solid areas. Purely cystic nodules (meaning 100% fluid-filled) are rarely cancerous.
Though a colloid thyroid nodule may increase in size, it remains in the thyroid and does not spread to other areas of the body.
It’s possible to develop other thyroid nodules, such as hyperplastic nodules and follicular adenomas. A goiter describes anenlarged thyroidthat either encompasses the entire gland or appears as bumpy nodules.
Some patients have more than one type of nodule at the same time.
What Is the Thyroid?
Symptoms of a Colloid Cyst on the Thyroid
Most thyroid colloid cysts do not produce any signs or symptoms unless they become large enough to affect surrounding tissues or are noticeable on the neck.
When thyroid colloid cysts have symptoms, they may include:
In some cases, thyroid nodules may produce hormones and cause symptoms ofoveractive thyroid (hyperthyroidism), including:
It’s also possible to have symptoms of anunderactive thyroid (hypothyroidism), such as:
Causes of Thyroid Colloid Cysts
Risk factors for developing thyroid nodules include smoking or living in areas with iodine deficiency (uncommon the U.S.). They become more common as you age.
For every 20 thyroid nodules that can be felt on physical examination, one is cancerous.Examples of cancerous thyroid nodules includepapillaryorfollicularcarcinomas,medullary cancer, oranaplastic cancer.
Exposure to ionizing radiation (from cancer treatments, occupational exposure, or nuclear fallout) increases thyroid cancer risk, especially if the exposure happened during childhood.Nodules that grow rapidly or cause a hoarse-sounding voice tend to be more concerning.
You may suspect that a painful thyroid nodule is cancerous. However, that’s not necessarily the case.Chronic inflammation of the thyroid gland can produce inflammatory nodules or a swollen thyroid gland.
Like many cancers, thyroid cancer can run in families. Your healthcare provider will take your family history and lifestyle factors into account when assessing your risk of thyroid cancer.
Nonfunctioning nodules (meaning they don’t produce thyroid hormone) have a 14% to 22% risk of being cancerous compared to hyperfunctioning nodules (nodules that produce thyroid hormone), which are rarely cancerous.
Although hyperfunctioning thyroid nodules don’t tend to cause cancer, they can result inother unpleasant side effects. By overproducing thyroid hormones, hyperfunctioning thyroid nodules can lead to symptoms of hyperthyroidism (including osteoporosis and abnormal heartbeats).
Ongoing monitoring andtreatmentcan help keep hyperfunctioning thyroid nodules under control.
Can Colloid Thyroid Cysts Turn Cancerous?Thyroid cysts rarely develop into cancer, but they can. Monitoring is required to determine whether a nodule is growing and may be turning cancerous. If you have multiple nodules, each one should be evaluated individually. If there’s growth or you have certain risk factors, additional testing for cancer may be needed.
Can Colloid Thyroid Cysts Turn Cancerous?
Thyroid cysts rarely develop into cancer, but they can. Monitoring is required to determine whether a nodule is growing and may be turning cancerous. If you have multiple nodules, each one should be evaluated individually. If there’s growth or you have certain risk factors, additional testing for cancer may be needed.
Isthmus Thyroid Nodules and Cancer Risk
Nodules are more common in women and the incidence increases with age. Depending on the size and location of a nodule, it may be palpable (able to be felt) during a physical exam. About 5% of women and 1% of men living iniodine-sufficient areashave palpable nodules.
Nonpalpable nodules are usually discovered through imaging studies such as anultrasound, computed tomography (CT) scan, or magnetic resonance imaging (MRI) of the neck or surrounding areas. High-resolution ultrasounds are particularly effective and detect thyroid nodules in up to 68% of healthy individuals.
How to Do a Thyroid Swallowing Test
If your healthcare provider finds a thyroid nodule, the next step is ordering a blood test to measure yourlevels of thyroid-stimulating hormone (TSH)andassess your thyroid function. Performing an ultrasound will help evaluate the type of nodule and check the surrounding lymph nodes in the neck.
Based on the results of these tests and other risk factors, further testing may be required. It can be helpful to undergo the following tests.
Radioactive Iodine Uptake Test
Imaging studies are performed six hours later, or even the next day.Waiting provides enough time to allow the radioactive iodine to reach the thyroid. The results of this test can determine if the nodule is hyperfunctioning (unlikely to be cancerous) or nonfunctioning.
About the Radioactive Iodine Uptake Test
Fine-Needle Aspiration (FNA)
For nonfunctioning nodules, fine-needle aspiration may be required (depending on the ultrasound findings and the size of the nodule). During this procedure, the practitioner inserts a thin needle through the skin and into the thyroid nodule to collect cells for testing.
Performing FNA while using an ultrasound machine helps ensure the correct placement of the needle. You may receive medication to numb the area of the neck to prevent discomfort. Your healthcare provider will take multiple cell samples from different areas of the nodule to analyze for cancerous characteristics.
Fine Needle Aspiration (FNA) Biopsy of the Thyroid
Molecular Testing
Sometimes the results of the FNA come back as “indeterminate” meaning the results are inconclusive as to whether the cells are cancerous or benign. Your healthcare provider may send the sample for molecular testing.Molecular testing analyzes the genetic sequence of the cells' DNA or RNA to check for mutations.
Thyroid Colloid Cyst Monitoring and Treatment
Many thyroid nodules remain stable in size. Some may shrink spontaneously or even disappear entirely without any treatment.Still, monitoring is important.
Benign thyroid nodules are monitored with a follow-up ultrasound one to two months after the initial discovery.If there has been no significant growth, repeat ultrasounds are typically performed every three to five years.
If your healthcare provider is concerned about a nodule’s growth rate, you may need another ultrasound or FNA testing to rule out cancer. These test results will help guide treatment and follow-up recommendations.
Surgical Removal
Cysts are usually noncancerous, but they occasionally contain cancerous solid components. Even benign cysts may require removal if they have significant growth.
Removal may be recommended in cases of:
Treatment options include:
Surgical removal usually requires general anesthesia, which puts you into a sleep-like state for the surgery. The surgeon usually makes the incision along the crease of the neck to avoid a scar and cuts out part or all of the thyroid.
If it’s thyroid cancer, surgery is typically done and there may be additionalthyroid cancer treatmentsrecommended, such as chemotherapy or radiation.
A Word From Verywell
Noticing a thyroid nodule on your neck or having one discovered during a routine examination can be alarming. There are several tests available to help your practitioner determine whether the nodule is concerning or harmless.
Most of the time, the only recommended treatment is ongoing monitoring to keep an eye out for any changes. Let your healthcare provider know if you suspect a growth on your thyroid so they can rule out potential dangers and you can learn more about the best next steps to take.
15 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Grani G, Sponziello M, Pecce V, Ramundo V, Durante C.Contemporary thyroid nodule evaluation and management.The Journal of Clinical Endocrinology & Metabolism. 2020;105(9):2869-2883. doi:10.1210/clinem/dgaa322Cleveland Clinic.Thyroid nodule.American Cancer Society.What is thyroid cancer?Johns Hopkins Medicine.Thyroid nodules.Penn Medicine.Thyroid nodules.Endocrine Society.Thyroid nodules.Johns Hopkins Medicine.Thyroid nodules: When to worry.American Academy of Family Physicians.Thyroid nodules: advances in evaluation and management.Durante C, Costante G, Lucisano G, et al.The natural history of benign thyroid nodules.JAMA. 2015;313(9):926. doi:10.1001/jama.2015.0956Haugen BR, Alexander EK, Bible KC, et al.2015 American Thyroid Association Management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer: the American Thyroid Association guidelines task force on thyroid nodules and differentiated thyroid cancer.Thyroid. 2016;26(1):1-133. doi:10.1089/thy.2015.0020UCLA Endocrine Center.Radioactive iodine uptake test.American Thyroid Association.Fine needle aspiration biopsy of thyroid nodules.New York Langone Health.Surgery for thyroid nodules and cancers.Johns Hopkins.Radiofrequency ablation.National Cancer Institute.Thyroid cancer treatment (adult)(PDQ)-patient version.
15 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Grani G, Sponziello M, Pecce V, Ramundo V, Durante C.Contemporary thyroid nodule evaluation and management.The Journal of Clinical Endocrinology & Metabolism. 2020;105(9):2869-2883. doi:10.1210/clinem/dgaa322Cleveland Clinic.Thyroid nodule.American Cancer Society.What is thyroid cancer?Johns Hopkins Medicine.Thyroid nodules.Penn Medicine.Thyroid nodules.Endocrine Society.Thyroid nodules.Johns Hopkins Medicine.Thyroid nodules: When to worry.American Academy of Family Physicians.Thyroid nodules: advances in evaluation and management.Durante C, Costante G, Lucisano G, et al.The natural history of benign thyroid nodules.JAMA. 2015;313(9):926. doi:10.1001/jama.2015.0956Haugen BR, Alexander EK, Bible KC, et al.2015 American Thyroid Association Management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer: the American Thyroid Association guidelines task force on thyroid nodules and differentiated thyroid cancer.Thyroid. 2016;26(1):1-133. doi:10.1089/thy.2015.0020UCLA Endocrine Center.Radioactive iodine uptake test.American Thyroid Association.Fine needle aspiration biopsy of thyroid nodules.New York Langone Health.Surgery for thyroid nodules and cancers.Johns Hopkins.Radiofrequency ablation.National Cancer Institute.Thyroid cancer treatment (adult)(PDQ)-patient version.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Grani G, Sponziello M, Pecce V, Ramundo V, Durante C.Contemporary thyroid nodule evaluation and management.The Journal of Clinical Endocrinology & Metabolism. 2020;105(9):2869-2883. doi:10.1210/clinem/dgaa322Cleveland Clinic.Thyroid nodule.American Cancer Society.What is thyroid cancer?Johns Hopkins Medicine.Thyroid nodules.Penn Medicine.Thyroid nodules.Endocrine Society.Thyroid nodules.Johns Hopkins Medicine.Thyroid nodules: When to worry.American Academy of Family Physicians.Thyroid nodules: advances in evaluation and management.Durante C, Costante G, Lucisano G, et al.The natural history of benign thyroid nodules.JAMA. 2015;313(9):926. doi:10.1001/jama.2015.0956Haugen BR, Alexander EK, Bible KC, et al.2015 American Thyroid Association Management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer: the American Thyroid Association guidelines task force on thyroid nodules and differentiated thyroid cancer.Thyroid. 2016;26(1):1-133. doi:10.1089/thy.2015.0020UCLA Endocrine Center.Radioactive iodine uptake test.American Thyroid Association.Fine needle aspiration biopsy of thyroid nodules.New York Langone Health.Surgery for thyroid nodules and cancers.Johns Hopkins.Radiofrequency ablation.National Cancer Institute.Thyroid cancer treatment (adult)(PDQ)-patient version.
Grani G, Sponziello M, Pecce V, Ramundo V, Durante C.Contemporary thyroid nodule evaluation and management.The Journal of Clinical Endocrinology & Metabolism. 2020;105(9):2869-2883. doi:10.1210/clinem/dgaa322
Cleveland Clinic.Thyroid nodule.
American Cancer Society.What is thyroid cancer?
Johns Hopkins Medicine.Thyroid nodules.
Penn Medicine.Thyroid nodules.
Endocrine Society.Thyroid nodules.
Johns Hopkins Medicine.Thyroid nodules: When to worry.
American Academy of Family Physicians.Thyroid nodules: advances in evaluation and management.
Durante C, Costante G, Lucisano G, et al.The natural history of benign thyroid nodules.JAMA. 2015;313(9):926. doi:10.1001/jama.2015.0956
Haugen BR, Alexander EK, Bible KC, et al.2015 American Thyroid Association Management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer: the American Thyroid Association guidelines task force on thyroid nodules and differentiated thyroid cancer.Thyroid. 2016;26(1):1-133. doi:10.1089/thy.2015.0020
UCLA Endocrine Center.Radioactive iodine uptake test.
American Thyroid Association.Fine needle aspiration biopsy of thyroid nodules.
New York Langone Health.Surgery for thyroid nodules and cancers.
Johns Hopkins.Radiofrequency ablation.
National Cancer Institute.Thyroid cancer treatment (adult)(PDQ)-patient version.
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