The short answer
There are four main types of thyroid cancer: papillary, follicular, medullary and anaplastic. Papillary is the most common. NCI says the differentiated types can usually be cured, while anaplastic grows and spreads quickly.
There are four main types: papillary, follicular, medullary and anaplastic.
Papillary is the most common type.
Papillary and follicular cancers can be treated and can usually be cured, NCI says.
Medullary thyroid cancer is sometimes caused by a gene change passed from parent to child.
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Why type matters more than "thyroid cancer" alone
This page explains the four main types of thyroid cancer and why your type matters. The thyroid is a small gland in the neck. It makes hormones that help control your metabolism. The National Cancer Institute (NCI) says the four types differ in how aggressive they are. Knowing your type changes what to expect.
Papillary and follicular: the differentiated types
Papillary is the most common type. Papillary and follicular cancers are called differentiated thyroid cancers. NCI describes them as well-differentiated tumors that can be treated and can usually be cured.
Medullary thyroid cancer: sometimes inherited
Medullary thyroid cancer starts in a different cell type, the C cells, rather than in the follicular tissue. NCI says it is sometimes caused by a change in a gene that is passed from parent to child. This is a change in the RET gene.
A genetic test can check for the changed gene. If a person has it, NCI says other family members may be tested to find out whether they are at higher risk.
Anaplastic thyroid cancer: grows and spreads quickly
Anaplastic thyroid cancer is made up of poorly differentiated or undifferentiated cells. NCI says these tumors grow and spread quickly and have a poorer chance of recovery. If your team tells you this is your type, ask how soon treatment should start and what the options are.
Signs that bring people to a doctor
NCI lists a lump (nodule) in the neck, trouble swallowing, trouble breathing and hoarseness among the signs of thyroid cancer. These can also have other causes. If you have trouble breathing, call 911 or your local emergency number.
Why the type matters
The type on your pathology report is one of the most important facts about your cancer. It helps guide treatment, which can include surgery, radioactive iodine for differentiated cancers, targeted drugs and radiation. It also affects the chance of recovery.
What to ask your team
- Which specific type of thyroid cancer do I have?
- Given my type, what is the expected course of treatment and outlook?
- If I have medullary thyroid cancer, should I have genetic testing, and should my relatives be tested too?
- How urgently does my type need to be treated?
Sources
Common questions
What are the main types?
There are four main types: papillary, follicular, medullary and anaplastic. Papillary is the most common. Papillary and follicular are called differentiated types, and NCI says they can be treated and can usually be cured.
What is medullary thyroid cancer?
It starts in the thyroid C cells rather than the follicular cells. It is sometimes caused by a gene change (in the RET gene) passed from parent to child. A genetic test can check for the changed gene, and relatives may be tested too.
What is anaplastic thyroid cancer?
It is made up of poorly differentiated or undifferentiated cells. NCI says these tumors grow and spread quickly and have a poorer chance of recovery.
Why does the type matter?
The type affects which treatments are used and the chance of recovery. Ask your team what your type means for you.
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Sources last checked: 2026-07-21 what this meansLast updated: 2026-10-02Next planned review: 2027-07-21
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Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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