Medullary Thyroid Cancer

Thyroiditis can cause either hyperthyroidism or hypothyroidism, or one followed by the other.

Common signs and symptoms of hyperthyroidism include:

• fast heart rate (100-120 beats per minute, or higher)
• nervousness or irritability
• increased perspiration
• muscle weakness (especially in the shoulders, hips, and thighs)
• trembling hands
• weight loss, in spite of a good appetite.

Common signs and symptoms of hypothyroidism include:

• slow heart rate (less than 70 beats per minute)
• feel slow or tired
• drowsy during the day, even after sleeping all night
• poor memory
• difficulty concentrating
• muscle cramps, numb arms and legs
• weight gain
• constipation
• heavy menstrual flow.

What are hot and cold nodules?

Thyroid nodules do not function like normal thyroid tissue. A thyroid image (scan) done with a radioactive chemical shows the size, shape, and function of the gland and of thyroid nodules. A nodule that takes up more of the radioactive material than the rest of the gland is called a hot nodule.

A nodule that takes up less radioactive material is a cold nodule. Hot nodules are seldom cancerous, but less than 10% of all nodules are hot. Cold nodules may or may not be cancerous. All lumps should be checked by your doctor.

How do doctors test nodules for cancer?

Your doctor can use several tests to find out whether or not a thyroid lump is cancerous.

• A thyroid image or scan shows the size, shape, and function of the gland. It uses a tiny amount of a radioactive chemical, usually iodine or technetium, which the thyroid absorbs from the blood. A special camera then creates a picture, showing how much iodine was absorbed by each part of the gland.
• In needle aspiration biopsy, a small needle is inserted into the nodule in an effort to suck out (aspirate) cells. If the nodule is a fluid-filled cyst, the aspiration often removes some or all of the fluid. If the nodule is solid, several small samples are removed for examination under the microscope. In over 90% of all cases, this testing tells the doctor whether the lump is benign or malignant.
• Ultrasound uses high-pitch sound waves to find out whether a nodule is solid or filled with fluid. About 10% of lumps are fluid-filled cysts, and they are usually not cancerous. Ultrasound may also detect other nodules that are not easily felt by the doctor. The presence of multiple nodules reduces the likelihood of cancer.

How are nodules treated?

Nodules that are thought to be benign are usually observed at regular intervals. Some patients may be advised to take thyroid hormone pills. In certain instances, the nodule may be surgically removed because of continuing growth, pressure symptoms in the neck, or for cosmetic reasons.

Fluid-filled cysts that come back after several aspirations may need to be removed.

If the testing shows a nodule that is, or might be, malignant (cancerous), your doctor will recommend surgery. (You should discuss special situations, such as pregnancy, with your doctor.) The goal of surgery is to remove as much of the cancerous tissue as possible. If the cancer is found in the early stages when it is still confined to the thyroid gland, the surgery is almost always successful. With papillary cancer, patients usually do well after treatment, even if the cancer has spread to the lymph nodes in the neck.

The surgeon starts by removing one lobe of the thyroid. This specimen is tested during surgery (frozen section) to tell the surgeon whether it is benign or malignant. If it is malignant, most or all of the thyroid is removed. If the cancer has spread, lymph nodes in the neck may also have to be removed. In addition, in patients with either papillary or follicular cancer, radioactive iodine therapy may be needed six weeks after surgery to destroy any remaining cancerous tissue.

What happens after surgery?

After surgery, patients must stay in the hospital for one to three days. They may also need to take some time off from work (one to two weeks for a desk job; three to four weeks for physical labor). Most patients do not have any trouble speaking or swallowing, and they report minimal pain after the surgery. In patients with thyroid cancer, a scan may be done approximately six weeks after surgery to detect any residual thyroid tissue that needs to be treated with radioactive iodine.

Patients with thyroid cancer will need to take thyroid hormone their entire lives. Some patients who have had a noncancerous nodule removed will also be advised to take thyroid hormone pills. These may prevent new nodules from forming in the remaining portion of the thyroid gland.

If you or a blood relative has Hashimoto’s thyroiditis or Graves’ disease, there is a chance that your children will inherit the problem. These diseases are also linked to other autoimmune conditions, such as premature gray hair, diabetes mellitus, arthritis, and patchy loss of skin pigment (vitiligo). You should tell your child’s doctor, so that the appropriate examinations can be performed.

Also, one out of every 4,000 infants is born without a working thyroid gland. If the problem is not corrected, the child will become mentally and physically retarded. Therefore, all newborns in the United States are tested for the disease. Once the problem is discovered and corrected, the child can grow up normally.