Thyroid Nodules

The thyroid is a butterfly-shaped gland in the neck that produces hormones that are important for growth and metabolism. A thyroid nodule is a lump that forms within the thyroid gland. Thyroid nodules can be solid or filled with fluid (cystic). Most thyroid nodules that develop in children are benign (not cancerous); however, careful evaluation is important to detect the 20 percent of thyroid nodules that are thyroid cancer.

Most thyroid nodules in children are discovered as a lump in the front of the neck found by the patient, by a parent, or by a physician during a routine examination. Some thyroid nodules are discovered by chance during medical imaging performed for another reason.

Most children with thyroid nodules feel fine and have no symptoms.

While symptoms may vary from child to child, the most common include:

• A visible lump in the neck
• A sensation of a lump in the throat when swallowing (or more rarely, difficulty with swallowing)
• Unexplained hoarseness

A rare type of thyroid nodule called an autonomous nodule (also known as a “toxic nodule” or “hot nodule”) can produce too much thyroid hormone. This can cause symptoms like:

• Weight loss
• Feeling too hot or sweaty
• Heart palpitations (heart racing, pounding, or “skipping beats”)
• Tremor of the hands
• Frequent bowel movements
• Difficulty concentrating

Autonomous nodules are usually benign, but special evaluation is needed to determine if a thyroid nodule is of this type.

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.

The causes of thyroid nodules in children are mostly unknown. Some factors that may increase the risk of developing thyroid nodules include exposure to radiation (such as from medical treatments) and certain genetic conditions that cause thyroid nodules or thyroid cancer. 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.

Sometime a lump in the neck that seems like a thyroid nodule is actually a thyroglossal duct cyst, which is a fluid-filled sac caused by an abnormality in how the thyroid forms during a baby’s development in the womb. Other types of neck masses and cysts sometimes can also be mistaken for thyroid nodules. Careful evaluation by an experienced team is necessary for suspected thyroid nodules, because thyroglossal duct cysts and other neck masses are evaluated and managed differently than true thyroid nodules.

Thyroid nodules in children should be evaluated by a physician with special expertise in this area, usually a pediatric endocrinologist. In addition to taking a medical history and performing a physical exam, the doctor may order certain tests.

• Blood tests are used to determine if the thyroid is working properly, or excessively.
• Ultrasound is the best imaging technique to visualize a known or suspected thyroid nodule. Ultrasound uses sound waves to assess the location and characteristics of nodules in the thyroid gland. Because ultrasound uses only sound waves, it does not expose the patient to any harmful radiation.
• Fine-needle aspiration (sometimes called a biopsy) uses a very thin needle to take a sample of a thyroid nodule. A pathologist examines the cells in the sample to determine whether the nodule may be a thyroid cancer. Not all thyroid nodules require a biopsy. If the doctor determines that a biopsy is needed, it can be performed on the same day as the ultrasound, almost always without sedation.
• Nuclear medicine imaging is used in some cases to determine if a thyroid nodule is producing too much thyroid hormone. Such autonomous nodules (also known as “toxic” or “hot” nodules) are usually benign (not cancer).
• Surgery is sometimes needed to determine whether a thyroid nodule is a thyroid cancer, if the result of fine-needle aspiration (biopsy) is not definitive.
• Genetic testing may be recommended in some cases when thyroid nodules occur as part of a possible genetic condition.

Treatment of a thyroid nodule will vary depending on the results of the evaluation.

Observation may be appropriate for thyroid nodules that do not require biopsy, or for nodules that are biopsied and found to be benign. Periodic ultrasounds may be recommended to monitor these nodules for changes, and additional biopsies may be needed in the future if changes are seen.

Surgery may be recommended to remove thyroid nodules that have abnormal biopsy results that suggest a possible thyroid cancer, or nodules that cause bothersome symptoms (like difficulty swallowing).

• Lobectomy is removal of one-half of the thyroid that contains a nodule.
  • Lobectomy may be appropriate to remove nodules that have a low risk of being cancer, including benign nodules that are removed just because they cause symptoms.
  • Lobectomy is a relatively quick and safe procedure, and most patients do not need to take thyroid medication afterward.
• Total thyroidectomy is removal of the entire thyroid gland.
  • Total thyroidectomy is usually appropriate for nodules that have a high risk of being cancer.
  • Lifelong treatment with thyroid medication is needed after total thyroidectomy.
  • This procedure is generally safe but rarely can have serious complications. For this reason, it is important that the procedure be performed by an experienced thyroid surgeon. Our thyroid surgeons have extensive experience in pediatric thyroid surgery and work closely with the rest of the Thyroid Center team to provide seamless, coordinated care before, during, and after surgery.

Autonomous nodules are usually benign. Their treatment depends on how much thyroid hormone they produce, and on whether this is causing symptoms of thyroid hormone excess.

• Autonomous nodules that are slightly overactive and cause no symptoms can often be observed without treatment.
• Nodules that are very overactive or that cause symptoms can be treated with medication, surgery, or (in patients over 18 years) radioactive iodine ablation.

Our approach to treating autonomous nodules is slightly different than that recommended by the American Thyroid Association, which recommends surgery for all autonomous nodules in children. Our approach is based on our extensive experience with this condition — which was published after the release of the American Thyroid Association guidelines — showing that with careful evaluation, some autonomous nodules can be managed safely without surgery.

Thyroglossal duct cysts and other neck masses are managed differently than thyroid nodules, often with surgical removal.

Children and adolescents with thyroid nodules are treated by the integrated multi-disciplinary team in the Boston Children’s Hospital Thyroid Center.

The Thyroid Center is one of the oldest and most experienced centers in the United States devoted exclusively to the care of children with thyroid diseases. The specialists in this multidisciplinary program have expertise in thyroid ultrasound, fine-needle aspiration, thyroid surgery, nuclear medicine imaging, and radioactive iodine therapy. Our investigators are at the forefront of research into the diagnosis and treatment of childhood thyroid nodules. Our recent findings have changed the way thyroid nodules in children are evaluated by showing that adult systems for thyroid nodule evaluation, which have long been applied directly to children, require modifications to work optimally in a pediatric population.