How Common is Thyroid Cancer in Children?

Thyroid cancer is rare in children, accounting for only about 1.8% of all thyroid cancer cases diagnosed annually. But it is one of the most treatable childhood cancers, with over 95% survival if caught early. This guide covers everything parents need to know about thyroid cancer in kids – from causes and diagnosis to treatment options and long-term outlook.

Incidence Rates in Children vs Adults

Thyroid cancer is an uncommon cancer in childhood. Fewer than 1 in 100,000 children develop thyroid cancer each year.

Although it can occur at any age, childhood thyroid cancer is most common in the teenage years, and it is the second most common cancer among adolescents ages 15 to 19.

By comparison, thyroid cancer is more common in adults. Over 44,000 adults are diagnosed annually, with incidence rates increasing with age. Thyroid cancer makes up around 2.3% of all new cancer diagnoses in the US.

Types of Thyroid Cancer in Children

There are four main types of thyroid cancer that can affect kids:

  • Papillary thyroid cancer (PTC) – Makes up about 90% of pediatric thyroid cancer cases. It is the most treatable type with an excellent prognosis.
  • Follicular thyroid cancer (FTC) – The second most common type, accounting for 5-10% of cases. Slightly more aggressive than PTC.
  • Medullary thyroid cancer (MTC) – Very rare in children at only 2% of cases. Can run in families.
  • Anaplastic thyroid cancer (ATC) – Almost exclusively occurs in older adults. Rarely affects children.

Symptoms of Thyroid Cancer in Kids

The most common symptom of pediatric thyroid cancer is a lump or nodule in the neck, often noticed by a parent.

Other signs and symptoms may include:

  • Hoarse voice or throat pain
  • Difficulty breathing or swallowing
  • Swollen lymph nodes
  • Unexplained tiredness

If thyroid cancer spreads, unusual lumps may be felt around the mouth, tongue, lips, or eyelids. However, distant metastases are uncommon in children.


Diagnosing Thyroid Cancer in Children

Diagnostic tests for thyroid cancer in kids may include:

  • Physical exam – The doctor will check for lumps, swelling, or enlarged lymph nodes in the neck.
  • Blood tests – To check levels of thyroid hormones and calcitonin.
  • Imaging tests – Ultrasound, CT, or MRI to evaluate the size and location of tumors.
  • Biopsy – Fine needle aspiration or surgical biopsy to extract cells for examination.

These tests help confirm diagnosis and determine the specific subtype of thyroid cancer.

Risk Factors and Causes

Most cases of pediatric thyroid cancer have no known cause. But these factors can increase risk:

  • Radiation exposure – From past radiation treatment or diagnostic imaging.
  • Genetic syndromes – Such as multiple endocrine neoplasia (MEN) syndromes.
  • Family history – Having a first-degree relative with thyroid cancer.
  • Iodine deficiency – Low iodine intake may play a role.
  • Being female – Thyroid cancer is 2-3 times more common in girls.

Treating Thyroid Cancer in Children

Most children with thyroid cancer will receive the following treatments:

  • Surgery – To remove part or all of the thyroid gland. A common procedure is total thyroidectomy.
  • Radioactive iodine therapy – Special iodine-131 capsules to destroy any remaining cancer cells.
  • Thyroid hormone therapy – Daily levothyroxine pills to replace hormones normally made by the thyroid.
  • Chemotherapy – Drugs to kill cancer cells, in rare aggressive cancers.
  • Targeted therapy – Newer drugs that attack specific molecular changes in cancer cells.

Treatment is tailored to the type and stage of cancer, minimizing long-term effects on development and growth.


Survival Rates and Outlook

Thyroid cancer has high survival rates in children when caught early:

  • Localized papillary thyroid cancer – Nearly 100% 5-year survival.
  • Regional follicular thyroid cancer – 98% 5-year survival.
  • Distant medullary thyroid cancer – 43% 5-year survival.

Overall 5-year survival rates exceed 90%, and many children are effectively cured with modern treatment. However, ongoing follow-up care is crucial, as cancer can recur years later.

Impact on Development and Growth

Thyroid cancer treatment can impact the development and growth of some children. Possible effects may include:

  • Delayed onset of puberty.
  • Impaired bone growth and increased risk of fractures.
  • Cognitive problems like poor memory or concentration.
  • Emotional and behavioral effects like depression, anxiety, and fatigue.

Careful hormone replacement and follow-up care can help minimize these risks. Most children go on to live normal, active lives after treatment.

Takeaways for Parents

Thyroid cancer remains rare in kids and is highly treatable. As a parent, you can take these steps:

  • Learn the symptoms and promptly report any unusual neck lumps or swelling to your child’s doctor.
  • Ask about genetic testing if there is a strong family history of thyroid cancer.
  • Work closely with your child’s care team to minimize treatment side effects and support healthy development.
  • Connect with support groups like the American Thyroid Association and ThyCa to get informational resources and advice from other families impacted by pediatric thyroid cancer.


Thyroid Cancer in the Pediatric Population – PMC

What Parents Need to Know About Thyroid Cancer in Children

Thyroid Cancer in Children

Thyroid Cancer Survival Rates, by Type and Stage

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