A nodule in the thyroid gland arises when a group of cells starts to grow. The cells can be benign or malignant. In most cases, a thyroid nodule is
benign. If a thyroid nodule is malignant, you have thyroid cancer.
Thyroid cancer
Thyroid cancer does not occur very often in children. Most of the cases in the Netherlands occur in teenagers, and there are only ten to fifteen cases per year. There are two types of thyroid cancer in children:
A nodule in your thyroid gland can also come from somewhere else. For example, it can be metastasis of a tumor somewhere else in the body or a lymphoma that is growing into your thyroid gland. Sometimes you get thyroid cancer because your throat was exposed to radiation in the past, for example, for the treatment of leukemia. The thyroid gland is extremely sensitive to this. The radiation can cause malignant cells to start growing.
Symptom pattern
A malignant thyroid nodule often feels relatively solid and can be sensitive or painful. The nodule can grow quickly. But sometimes you will not notice it, for example if it is very small or if it is at the backside of the thyroid gland. In that case, you do not receive a warning that something is wrong. Also, because your thyroid gland usually continues to function normally.
Metastases occur more commonly in children than in adults. In children, thyroid cancer is often discovered late, because they often have no symptoms or complaints. Sometimes you discover the cancer, because the lymph gland in your throat is swollen. In this case, the thyroid cancer has metastasized to your lymph gland. Metastases to the lungs, liver, bones and brain also occur.
Diagnostics
If you have symptoms of thyroid cancer, you will undergo a number of tests. Blood samples will be taken to test thyroid function (FT4 and
TSH), and an
ultrasound of your thyroid gland and throat will be performed. If you have medullary thyroid cancer, there will be more calcitonin and CEA (carcinoembryonic antigen) in your blood.
Ultrasound. The thyroid gland and the lymph glands can be clearly seen on an ultrasound. You can see the structure of the thyroid gland, how large it is and whether you have a nodule. The nodule will also be thoroughly examined: how large it is, where it is (in the thyroid gland or outside of it), and how it looks (containing clear fluid, like in a cyst, or specks of calcium).
Needle biopsy. To determine whether the cells in the nodule are benign or malignant, some tissue is taken and examined. In order to do this, the nodule must be large enough to prick with a needle, at least one centimeter. This tissue sample is taken with a procedure called a needle biopsy. A thin needle is used to prick the thyroid gland; the needle's path is monitored via ultrasound. Using ultrasound, the needle can be guided in such a way that the tip of the needle is directed precisely into the nodule. Then, a small piece of tissue is sucked out of the nodule and is later examined. This examination takes approximately ten days; in other words, you do not get the results immediately. During the needle biopsy procedure, you must remain motionless. To lessen the sensation of the needle prick, an anesthetic cream is applied. The result of a needle biopsy is not always clear-cut. To know for sure if it is thyroid cancer, an operation may be needed. During the operation, the half of the thyroid gland that contains the nodule is removed. This tissue can then be examined further in the laboratory.
Differentiated thyroid cancer
This type of cancer arises in those thyroid cells which produce thyroid hormone. There are two types of differentiated thyroid cancer, papillary and follicular. The papillary form is most common.
Differentiated thyroid cancer occurs more frequently in children with PTEN Hamartoma Tumor Syndrome (PHTS). Genetic testing can uncover the PTEN mutation (an alteration in the PTEN gene). Possible features of PHTS are larger-than-average head size, delayed development, and abnormalities of the skin and mucous membranes.
The treatment for this type of cancer is the surgical removal of the entire thyroid gland (total thyroidectomy). If metastasis to the lymph glands in the throat has occurred, then all of the lymph glands in the throat are removed. This operation is performed under general anesthesia. The removal of the thyroid gland must be performed very carefully due to the vulnerable nerves and the parathyroid glands which are situated near to it. To be sure that all cancer cells have been removed, a radioactive iodine treatment is also given after the surgery. Differentiated thyroid cancer cells are very sensitive to this treatment, so it destroys them completely. Once the thyroid gland has been removed, you must take levothyroxine (thyroid hormone) every day. In addition, the functioning of the parathyroid glands must also be carefully monitored.
The prognosis for differentiated thyroid carcinoma is good, even if it has metastasized. The cancer may return in the place where the thyroid gland once was or in the lymph glands. That is why you must regularly go to the hospital for check-ups. A radioactive iodine uptake test will show whether the thyroid gland tissue and any metastases are gone. Your blood will also be tested for the
Tg protein. The only place this protein is produced is in the thyroid gland, so you should no longer have any Tg in your blood.
Medullary thyroid cancer
This type of cancer arises in the C cells of your thyroid gland. The C cells are nestled between the follicles in the thyroid gland. They do not produce thyroid hormone, and they do not take up any iodine. Medullary thyroid cancer is very rare. It occurs primarily in children with Multiple Endocrine Neoplasia (MEN) Type 2 syndrome. As a result of an alteration on a gene, these children develop malignant tumors in hormone-producing glands and organs. Genetic testing can be used to diagnose this syndrome and determine which mutation (alteration) in the RET gene is involved.
The treatment is difficult and complicated. If genetic testing shows that MEN syndrome runs in your family, the entire thyroid gland will be removed surgically (total thyroidectomy). For some mutations, this is done even before the child's first birthday. The entire thyroid gland will also be removed if medullary thyroid cancer is diagnosed later in life. If metastasis to the lymph glands in the throat has occurred, then all of the lymph glands in the throat are removed. This operation is performed under general anesthesia. The removal of the thyroid gland must be performed very carefully due to the vulnerable nerves and the parathyroid glands which are situated near to it. Once the thyroid gland has been removed, you must take levothyroxine (thyroid hormone) every day. In addition, the functioning of the parathyroid glands must also be carefully monitored. Treatment with radioactive iodine cannot be used for this disorder, because these types of cancer cells are not sensitive to it.
The course of this illness is different for everyone. If the cancer has metastasized, the outlook is less positive, and it is very difficult to get the disease under control. That is why you must regularly go to the hospital for check-ups, among others to follow up how much CEA and calcitonin are in your blood.
Benign thyroid nodules
If you have a benign thyroid nodule and your thyroid gland is functioning normally, you usually will not need any treatment. However, you must go to the hospital for a check-up every six months. There, your blood will be tested (FT4, TSH), and an ultrasound of your throat will be performed. If nothing has changed or if the nodule has become smaller, you don't need to do anything. If the nodule becomes larger after some time, a second biopsy may be necessary, since a benign nodule may become malignant over time.
Benign thyroid nodules which may occur in children and adolescents:
Diagnostics
If you feel a nodule in your thyroid gland, further examination is necessary. Blood samples will be taken to test thyroid function (FT4 and TSH), and an ultrasound of your thyroid gland and your throat will be performed. The amount of CEA (carcinoembryonic antigen) and calcitonin in your blood may also be measured. In benign nodules, these values are not elevated. In malignant nodules (medullary thyroid cancer), they are elevated.
Ultrasound. The thyroid gland and the lymph glands can be clearly seen on an ultrasound. You can see the structure of the thyroid gland, how large it is and whether you have a nodule. The nodule will also be thoroughly examined: how large it is, where it is (in the thyroid gland or outside of it), and how it looks (containing clear fluid, like in a cyst, or specks of calcium).
Needle biopsy. To determine whether the cells in the nodule are benign or malignant, some tissue is taken by means of a needle biopsy. In order to do this, the nodule must be large enough to prick with a needle, at least one centimeter. The thyroid gland is pricked with a thin needle. Using ultrasound, the needle can be guided in such a way that the tip of the needle is directed precisely into the nodule. Then, a small piece of tissue is sucked out of the nodule and is later examined in the laboratory. This examination takes approximately ten days; in other words, you do not get the results immediately. During the needle biopsy procedure, you must remain motionless. To lessen the sensation of the needle prick, an anesthetic cream is applied. The result of a needle biopsy is not always clear-cut. If there is some doubt about the nature of the nodule, surgery may be required. During the operation, the half of the thyroid gland that contains the nodule is removed. This tissue can then be examined further in the laboratory.
Adenoma
A follicular adenoma is a nodule of thyroid hormone-producing cells. The diagnosis is made based on an ultrasound with a needle biopsy. You must also make regular visits to the hospital to check up on the development of the nodule.
If you have a toxic adenoma, you will produce extra thyroid hormone. This may result in
the development of hyperthyroidism. A toxic adenoma does not disappear on its own; the nodule is usually removed surgically.
Cysts
A cyst is a cavity filled with fluid. The amount of fluid can fluctuate, which means the cyst can become larger and smaller. The diagnosis is made based on an ultrasound with a needle biopsy. The fluid in the cyst is sucked up through the needle, and then the cells are examined. Sometimes after the biopsy, the cyst disappears completely. If the cyst returns and the cells are benign, you must come for regular check-ups. If the testing of the cells does not
result in a clear-cut diagnosis, the cyst is surgically removed and further examined. Thyroid cysts do not occur very often in children.
Multinodular goiter
You may have more than one nodule, and if your thyroid gland is also working too quickly, then you have what is called toxic multinodular goiter. This disorder can be identified using a blood test, an ultrasound and a radioactive iodine uptake test. With toxic multinodular goiter, you will not have any autoantibodies (
TSI) in your blood. A radioactive uptake test will reveal the increased uptake of iodine and also the activity level of the nodules. Multinodular goiter does not occur very frequently. It does, however, occur more frequently in children with McCune-Albright Syndrome. Approximately one in three such children develops this type of hyperthyroidism. The treatment consists of taking medication (antithyroid medicines), although surgery or radioactive iodine treatment often becomes necessary after some time.
