Thyroid cancer is a rare type of cancer in children. It responds well to treatment, and children with this cancer are expected to make a full recovery.

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Thyroid cancer is a type of cancer that grows in the thyroid, which is a butterfly-shaped gland in the lower part of the neck. Your thyroid secretes thyroid hormone, which helps control things like energy levels, metabolism, heart rates, and the functioning of multiple organs in the body.

Thyroid cancer in children is rare. Only 1.8% of all thyroid cancers diagnosed in the United States are in children.

Thyroid cancer is highly treatable. The vast majority of children with this cancer have positive outcomes.

In this article, we go through everything parents need to know about thyroid cancer in children, including symptoms, causes, risk factors, diagnosis, treatments, and prognosis.

Thyroid cancer occurs when cancerous cells begin to proliferate in the thyroid gland.

Thyroid cancer is far less common in children than in adults. Although thyroid cancer can be more aggressive in children than in adults and tends to recur more frequently, it responds very well to treatment.

That said, the rate of thyroid cancer in children appears to be growing, with rates increasing 9.5% every year between 2006 and 2013.

According to a 2019 investigation, these higher numbers may be because of better detection of thyroid cancer in children, but also because of unknown causes or increased environmental exposures.

Either way, treatment for thyroid cancer in kids continues to produce extremely favorable results.

Types of thyroid cancer in children

The American Thyroid Association outlines the four kinds of thyroid cancer in children:

  • Papillary thyroid cancer (PTC) is the most common type of thyroid cancer in kids, with 90% of cases in children being this type. It’s a slow-growing cancer but can spread to the lymph nodes. Even when it has spread, it has a very favorable outlook.
  • Follicular thyroid cancer (FTC) is the second most common type of thyroid cancer in kids. It encompasses 5–10% of all cases. FTC can spread to lymph nodes and organs like the lungs and bones. The outlook is also good for this type.
  • Medullary thyroid cancer (MTC) is very rare. Only 2% of thyroid cancers in children are this type. MTC is often hereditary but not always.
  • Anaplastic thyroid cancer (ATC) is exceedingly rare and almost always occurs in adults.

Finding a bump in your child’s thyroid area usually doesn’t mean your child has thyroid cancer. Lumps on the thyroid are called nodules. They typically don’t need treatment. Only 1 in 5 nodules are cancerous.

Some potential signs of thyroid cancer in children include:

  • a noticeable lump on the neck
  • labored breathing
  • difficulty swallowing
  • voice changes, including increased hoarseness
  • unusual, painless bumps on your child’s tongue, lips, or eyelids
  • decreased tear production
  • unusually tall, thin stature, along with longer than usual arms, fingers, legs, and toes

The exact cause of thyroid cancer in children is unknown. But two things that may increase the risk are radiation exposure and genetics.

Radiation exposure can happen during medical procedures or cancer treatments but can also occur as a result of environmental exposure to high levels of radiation.

Although rare to begin with, any child can get thyroid cancer, with or without a specific risk factor.

However, there may be certain children who have a higher risk than others. Thyroid cancer in children occurs mostly in adolescents. It’s more commonly seen in adolescent females than in adolescent males by a 6:1 ratio by ages 15–19 years.

Risk factors for thyroid cancer in children include:

  • exposure to radiation during medical testing, medical treatments, or environmental exposure
  • having a genetic syndrome, including multiple endocrine neoplasia type 2A (MEN2A) syndrome or multiple endocrine neoplasia type 2B (MEN2B) syndrome
  • having a family history of thyroid cancer or a close relative with the condition

A history of Hodgkin’s lymphoma is another risk factor. According to a 2022 multicenter international study, children who have previously had Hodgkin’s lymphoma or were ages 5 years or younger at the time of radiation exposure are more likely to develop thyroid cancer.

The main complication of thyroid cancer in children is that it can spread beyond the thyroid into other areas of the body or other organs.

The other potential complication is that if your child’s thyroid has to be removed during treatment, they will need to take thyroid hormone medication for the rest of their life because their thyroid will no longer be available to naturally produce it.

The treatment for thyroid cancer in children depends on the type of cancer and how much it has spread.

The first line of treatment for thyroid cancer is surgery to remove the cancer. Depending on the location and size, a child’s entire thyroid or part of it will be removed.

Children who have their entire thyroid surgically removed need to take thyroid hormone medication for the rest of their lives.

If all of the cancerous tissue can’t be removed, or if the cancer has spread elsewhere, a type of therapy called radioactive iodine (RAI) will be used. This treatment destroys any remaining thyroid tissue cells in the body.

Thyroid cancer in children is highly treatable. Children’s outlooks are very positive.

The survival rate for children with thyroid cancer is 95% even over a follow-up period of 20–30 years, according to the American Thyroid Association.

If your child’s doctor suspects thyroid cancer, they will run several diagnostic tests. These may include:

  • physical exams and medical history to check for thyroid cancer symptoms
  • blood tests to assess thyroid functioning
  • thyroid scan, which uses radioactive material to create images of the thyroid
  • imaging tests like CT scans, MRIs, ultrasounds, and X-rays to create visual images of the thyroid
  • biopsies to test the thyroid tissue for cancer cells

Thyroid cancer in children sounds scary, but it’s rare and highly treatable. Symptoms include a lump near the thyroid gland, trouble breathing, and vocal changes.

Many of these symptoms resemble other conditions, so diagnosis requires a full medical workup, including imaging tests, blood tests, and biopsies.

Surgery is the main way to treat thyroid cancer. The majority of children are free of thyroid cancer after treatment.