The thyroid is a butterfly-shaped gland that is normally located in lower front part of the neck. The thyroid produces hormones that help to ensure normal growth and development and that the body’s energy, metabolism, heart, muscles, and other organs are working properly.

What causes thyroid nodules?

Thyroid nodules are growths in the gland that occur more frequently in adults but can present in childhood. Thyroid nodules can be associated with underlying autoimmune disease, where your child’s body produces antibodies against the thyroid gland. In addition, iodine deficiency (uncommon in the United States) can lead to enlargement of the thyroid gland and development of thyroid nodules.
There is an increased risk of thyroid cancer in nodules found in children and adolescents compared to adults; however, even in children, most thyroid nodules are benign (not cancer). About 75% of nodules found in children and adolescents are benign. Children with thyroid nodules need to be followed closely by a multidisciplinary team of pediatric endocrinologists and surgeons. Risk factors for thyroid cancer include personal history of neck radiation or family history of thyroid cancer.

How is thyroid nodule diagnosed?

Thyroid nodule is usually discovered when your child’s neck is noted to be enlarged or swollen by your child, you, or your child’s doctor. Blood tests will be ordered which will include measurement of thyroid hormone (thyroxine, or T4) and thyroid-stimulating hormone (TSH) in your blood to determine whether your thyroid is functioning normally. Your child will be referred to pediatric endocrinologist and pediatric surgeon for evaluation when at thyroid nodule is found.

Physical examination and blood tests alone cannot determine whether thyroid nodule contains cancer. The thyroid nodule(s) will need to be evaluated by specialized tests such as thyroid ultrasound and fine needle biopsy.

Thyroid Ultrasound

Thyroid ultrasound uses high-frequency sound waves to obtain a picture of the thyroid. The ultrasound is a painless test and is done by radiologist. This test can determine the precise size of the nodule, whether the nodule is solid or fluid filled (cystic) and identify certain features of the nodule that may be concerning for cancer. If the nodule has features that are concerning for cancer, your child will need a special procedure to take a small sample of the nodule to be examined under a microscope. If the nodule has features that are not concerning for cancer or does not require surgery to be removed, ultrasound is useful to monitor the nodule to see if it shrinks or grows over time. The interval of time between thyroid ultrasound will be determined by your child’s doctor.

Thyroid Fine Needle Aspiration Biopsy (FNA or FNAB)

A fine needle biopsy of a thyroid nodule is a special procedure to take a small sample of the nodule to be examined under the microscope. The needle used for the procedure is very small. If the nodule is large and can be felt on physical examination, this simple procedure can be done in the drop-in FNA clinic at UCSF Benioff Children’s Hospital at San Francisco. The appointment can be done on the same day that your child is seen by the pediatric surgeon. The results of the biopsy can come back the same day. If the nodule is small and can only be seen on ultrasound, your child’s pediatric surgeon will help schedule an appointment with the radiologist who will perform this simple procedure using ultrasound for guidance. This will be scheduled on a different day. The results of this biopsy may take up to 5 business days to come back. The cells taken from the nodule during the biopsy are then examined under a microscope by a pathologist.

The report of a thyroid fine needle biopsy will usually indicate one of the following findings:

  • The nodule is benign (not cancer). This is the most common result. The risk of cancer is low (about 3%). These nodules usually are not recommended to be removed with surgery. Follow up ultrasound exams are important. Occasionally, another biopsy may be required in the future, especially if the nodule grows over time.
  • The nodule is malignant (cancer) or suspicious for malignancy. This happens in about 5% of the biopsies done on thyroid nodules. The most common type of cancer is papillary thyroid cancer. A suspicious biopsy has a 50-75% risk of cancer in the nodule. These nodules require surgical removal of the entire thyroid gland
  • The nodule is indeterminate. An Indeterminate finding means that even though an adequate number of cells was removed during the fine needle biopsy, examination with a microscope cannot reliably classify the result as benign or cancer. Therefore, surgery to remove the one side of the thyroid gland that contains the nodule is recommended. If a cancer is found, another operation is required to remove the remaining thyroid gland. If the first surgery confirms that no cancer is present, no additional surgery is needed.
  • The biopsy may also be nondiagnostic or inadequate. This result indicates that not enough cells were obtained to make a diagnosis but is a common result if the nodule is a cyst. These nodules may require reevaluation with second fine needle biopsy, or may need to be removed surgically depending on the clinical judgment of your doctor.

Molecular Diagnostics

Can any other tests assist in evaluation of thyroid nodules?

Our hospital in San Francisco offers additional specialized tests that examine the genes in the DNA of thyroid nodules. These tests are done on samples obtained during the fine needle biopsy procedure and can provide helpful information about whether cancer may be present or absent. These tests are not available at all institutions and are particularly helpful when the specimen evaluated by the pathologist is indeterminate.

How is thyroid nodule treated?

Children with any thyroid nodules found to contain thyroid cancer, or that are suspicious for cancer, should have surgery to remove the nodule and all the thyroid gland. More than 90% of thyroid cancers in children are papillary thyroid cancer. The majority of children do very well and live long, healthy lives after a thyroid cancer diagnosis.

Surgery to remove only one side of the thyroid gland is called right or left thyroidectomy. Surgery to remove the entire thyroid gland is called total thyroidectomy.

The thyroid gland sits in the lower front part of the neck. Located behind the thyroid are four small pea-sized parathyroid glands that produce hormone for calcium balance in the body. In addition, each side of the neck has a special nerve called the recurrent laryngeal nerve that helps the vocal cords move in the throat. The vocal cords move to help to produce sound when your child talks. During surgery to remove either one side of the gland or the entire thyroid gland, care is taken to preserve these structures. Surgery to remove the thyroid gland involves an incision (about 2 inches in length) along the skin crease in the lower half of the neck.

How long will my child be in the hospital?

Children will stay in the hospital for one night after surgery. If the entire thyroid gland is removed, blood tests will be taken at frequent intervals after surgery to make sure the calcium levels remains normal. Sometimes, your child will need to take calcium supplements after a surgery for a short period of time (weeks or months after surgery). Your child usually only need to take Tylenol or ibuprofen for pain after surgery.

What is expected after surgery?

After removal of only one side of the thyroid gland, your child will still grow and develop normally because the remaining part of the thyroid will produce normal level of thyroid hormone. Your child will need follow-up ultrasound to monitor the remaining gland for the development of nodules. The interval time for the ultrasound will be determined by your child’s endocrinologist.

After the removal of the entire thyroid gland, your child will need to take thyroid hormone supplement every day for the rest of their life. Blood tests will be done to monitor the level of the thyroid hormone in your child’s body, and the medication will be adjusted as needed by your child’s endocrinologist. If the thyroid gland was removed for cancer, it is very important for your child to take this medication, to stop any remaining thyroid cells in the neck from growing and the cancer from returning. Your child’s endocrinologist will follow your child closely in clinic and will order blood tests and repeat ultrasounds to make sure the thyroid cancer does not return. Your child’s endocrinologist will also talk to you and your child about another treatment for thyroid cancer after surgery called radioactive iodine. This treatment is used to kill any thyroid cells that are remaining in the neck after surgery. The decision to offer this treatment to your child will be determined by the endocrinologist after discussing the risks and benefits to your child.