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Cancer Explained
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Types of Thyroid Cancer

A plain-language explanation of the main types of thyroid cancer, most of which are highly treatable. Based on the National Cancer Institute.

NCI source

Last reviewed: 2026-07-07

The short answer

Most thyroid cancers are differentiated types — papillary and follicular — which grow slowly and are highly treatable. Less common types include medullary and anaplastic thyroid cancer. The type strongly affects treatment and outlook.

  • Most thyroid cancers are papillary or follicular, which are highly treatable.

  • Papillary thyroid cancer is the most common type and usually grows slowly.

  • Medullary thyroid cancer is less common and can run in families.

  • Anaplastic thyroid cancer is rare but fast-growing.

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The full explanation.

The simple version

Thyroid cancer is not a single disease. Most thyroid cancers are slow-growing, highly treatable types, but a few are less common and behave differently. Knowing the type is important for treatment and outlook.

The common types

Most thyroid cancers are 'differentiated' types:

  • Papillary — the most common; usually slow-growing and highly treatable
  • Follicular — the next most common; also usually treatable

Less common types

Medullary thyroid cancer starts in different thyroid cells and can sometimes run in families, so genetic testing may be offered. Anaplastic thyroid cancer is rare but fast-growing and harder to treat.

Most thyroid cancers are papillary or follicular types, which are highly treatable.

Why it matters

The type strongly affects treatment and the outlook. The common papillary and follicular types usually have an excellent outlook, especially when found early. Doctors confirm the type by examining tissue.

Words to know

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Common questions

What are the main types?

Most thyroid cancers are 'differentiated' types — papillary (the most common) and follicular — which grow slowly and are highly treatable. Less common types are medullary and anaplastic thyroid cancer.

What is medullary thyroid cancer?

It is a less common type that starts in different thyroid cells and can sometimes run in families. People with it may be offered genetic testing.

What is anaplastic thyroid cancer?

It is a rare, fast-growing type that is more difficult to treat than the common differentiated types. It is much less common.

Why does the type matter?

The type strongly affects treatment and the outlook. The common papillary and follicular types usually have an excellent outlook, especially when found early.

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  1. Q1.What is the most common type of thyroid cancer?
  2. Q2.Which type can run in families?
  3. Q3.How are the common types described?

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Types of Thyroid Cancer