What Is the Thyroid?
The thyroid is a small gland located below the skin and muscles at the front of the neck, just at the spot where a bow tie would rest.
It's brownish red, with left and right halves (called lobes) that look like a butterfly's wings. It usually weighs less than an ounce, but helps the body do many things, such as get energy from food, grow, and go through sexual development.
What Is Thyroid Cancer?
Cancer happens when cells grow in a way that the body can no longer control. Thyroid cancer is when these cell problems start in the thyroid gland. These cancer cells can spread to other areas of the body.
Thyroid cancer is uncommon in children. When it does happen, the results of treatment are usually excellent.
Types of Thyroid Cancer
The kinds of thyroid cancer that kids and teens can develop include:
Papillary: This is the most common kind of thyroid cancer in children. It begins in cells that make thyroid hormones containing iodine. This kind of cancer grows very slowly, but can spread to the lymph nodes in the neck and, rarely, other parts of the body.
Follicular: This cancer also begins in thyroid hormone-producing cells. It's more likely than papillary thyroid cancer to spread to other parts of the body, but is less common in children.
Medullary: This rare cancer begins in cells that make calcitonin, not iodine. It tends to spread to other parts of the body. Kids who develop it usually have certain inherited genetic conditions.
What Are the Signs & Symptoms of Thyroid Cancer?
Often, thyroid cancer won't cause any symptoms early on. As the cancer grows, it can cause:
- neck and throat pain, or a feeling of fullness
- a lump (nodule) that can be felt through the skin
- voice changes, such as hoarseness
- trouble swallowing or breathing
- swollen lymph nodes (swollen glands) in the neck
Who Gets Thyroid Cancer?
Certain things can increase a child's risk for thyroid cancer. Teen girls, for instance, develop thyroid cancer more often than young girls or males of any age. Other risk factors include:
- previous radiation treatment (for instance, for another cancer, especially if it involved the head, neck, or chest)
- having an autoimmune thyroid disease (such as Hashimoto's thyroiditis)
- a family history of thyroid cancer
How Is Thyroid Cancer Diagnosed?
To diagnose thyroid cancer, doctors will examine the head and neck to look for lumps. They may order blood tests to see how the thyroid is working and do a neck ultrasound.
If a thyroid nodule is found, a thyroid scan can tell the doctor what type of nodule it is. For this test, a person swallows a pill containing a small amount of radioactive iodine (a "tracer"), which the thyroid absorbs. Then, a special camera measures where the radioactive iodine is taken up by the thyroid, giving the doctor a better picture of the location, size, and type of nodule.
Often, a similar test — a radioactive iodine uptake (RAIU) test (also called a thyroid uptake) — is done along with the thyroid scan if the thyroid is overactive. It also involves scanning the thyroid after someone takes the radioactive iodine pill. The person lies on his or her back while a device called a gamma probe moves over the neck. This will show if the iodine is absorbed evenly by the thyroid, an indication that the gland is working well.
A fine-needle biopsy also can be done to see if a nodule is cancerous. During the biopsy, the doctor inserts a thin needle through the skin into the thyroid nodule (the skin is numbed with medicine first). Through the needle, the doctor takes a sample of tissue or some fluid from a cyst. The tissue or fluid is then sent to a lab to be examined. In some cases, a person might need to have the nodule surgically removed for more detailed examination in the lab.
How Is Thyroid Cancer Treated?
Treatment of many thyroid conditions — including thyroid cancer — involves surgery to remove part or all of the gland.
Types of surgeries used include:
- Thyroid lobectomy. If there's a nodule in just one half of the thyroid, the surgeon removes the lobe that contains it. Also called a hemi-thyroidectomy.
- Isthmusectomy. This is surgical removal of the bridge of thyroid tissue (the isthmus) between the two lobes. This is done to treat small tumors in the isthmus.
- Total or near-total thyroidectomy. Surgical removal of all or most of the thyroid. This is most commonly
Anyone who has a thyroidectomy will need to take a thyroid hormone replacement pill. Kids who had the operation because of thyroid cancer will usally get a higher dose of hormone replacement. This is called supressive therapy, and works by raising T4 (thyroxine) levels while lowering TSH (thyroid stimulating hormone) to prevent thyroid cells from growing.
Radioactive iodine, used in thyroid scans and RAIU tests, also can treat thyroid cancer. After surgery, radioactive iodine therapy (RAI) is used to destroy any thyroid cells that remain. The thyroid absorbs almost all the iodine the body takes in, so using radioactive iodine keeps the radioactive material in the gland, helping to prevent side effects in other parts of the body.
What Else Should I Know?
Thyroid cancer is rare in kids. When it happens, most kids who get treated promptly have an excellent recovery and go on to lead normal, healthy lives.