Thyroid Cancer in Children | Symptoms & Causes

What causes thyroid cancer in children?

The vast majority of thyroid cancers in children have no known cause. However, there are some known risk factors for developing thyroid cancer, including radiation exposure and certain genetic conditions. What causes some children to develop thyroid nodules and thyroid cancer is an area of active research in our Thyroid Center.

  • Exposure of the thyroid to radiation, including radiation used to treat other cancers, increases the risk of developing thyroid nodules and thyroid cancer. Some other childhood cancers that are sometimes treated with radiation that may affect the thyroid include leukemias, lymphomas, brain tumors, and neuroblastomas, as well as cancers that require a bone marrow transplant. The younger a child is when exposed to radiation, the more the risk of thyroid nodules and cancer is increased.
  • Thyroid nodules and cancer can occur as part of certain genetic conditions. Some of these conditions may be inherited (familial), and some can occur just in the child without being present in the parents. Some genetic syndromes that increase the risk of thyroid nodules and cancer include:
    • PTEN hamartoma tumor syndrome may include features like a large head; vascular malformations; neurodevelopmental disorders; and tumors of many organs including the skin, breast, uterus, and thyroid. Thyroid nodules and thyroid cancer can occur in patients with PTEN mutations as young as 6 years old. (PTEN syndromes also include several other syndromes like Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, and Proteus syndrome).
    • DICER1 syndrome increases the risk of several types of tumors, including tumors of the lungs (often in infancy), ovaries, kidneys, and thyroid.
    • Familial adenomatous polyposis (FAP) causes the growth of numerous polyps (abnormal growths or tumors) in the gastrointestinal tract. It also causes an increased risk of other tumors, including thyroid cancer.
    • Multiple endocrine neoplasia type 2 (MEN2) is a familial condition that causes medullary thyroid cancer, sometimes in childhood or even infancy, as well as tumors of the adrenal glands (pheochromocytomas) and sometimes the parathyroid glands.
    • Familial medullary thyroid carcinoma (FMTC) is a familial form of medullary thyroid cancer that is similar to MEN2 except that it does not cause any other types of tumors.

What are the symptoms of thyroid cancer in children?

Most children who are diagnosed with thyroid cancer feel well at the time of diagnosis, and many have no symptoms at all. While symptoms may vary from child to child, the most common include:

  • a lump in the neck
  • swollen lymph nodes in the neck
  • a sensation of a lump in the throat when swallowing (or more rarely, difficulty with swallowing)
  • unexplained hoarseness

Keep in mind that similar symptoms can be associated with more common medical problems and conditions. Therefore, it is important to consult your child's physician for a diagnosis if your child has one of these symptoms.