Thyroid cancer generally presents as a nodule, lump, or mass in the thyroid. Less commonly, a swollen gland or lymph node in the neck may be the initial manifestation of the disease.

The thyroid is a butterfly-shaped gland located at the base of your neck, just below your Adam's apple. Although the thyroid gland is small, it produces hormones that regulate every aspect of your metabolism, from your heart rate to how quickly you burn calories.

Sometimes you may develop one or more solid or fluid-filled lumps in your thyroid, called nodules. The great majority of these nodules are noncancerous (benign) and cause no symptoms. Approximately 5 percent of nodules are malignant.

For most of these people, the prognosis is excellent. The most common types of thyroid cancer can often be completely removed with surgery. What's more, five-year survival rates are among the highest of any type of cancer - more than 90 percent.

Signs and symptoms

Most often, you won't have signs and symptoms in the early stages of thyroid cancer, but as the cancer grows, you may experience one or more of the following:

• A lump — sometimes growing rapidly — in the front of your neck, just below your Adam's apple

• Hoarseness or difficulty swallowing

• Trouble breathing

• Swollen lymph nodes, especially in your neck

• Pain in your throat or neck, sometimes spreading up to your ears

Having one or more of these symptoms doesn't necessarily mean you have thyroid cancer. Other conditions — including a benign thyroid nodule, an infection or inflammation of the thyroid gland, or a benign enlargement of the thyroid (goiter) — can cause similar problems, all of which are highly treatable.

• Goiter

Causes

Your thyroid gland is composed of two lobes that resemble the wings of a butterfly separated by a thin section of tissue called the isthmus. The thyroid takes up iodine from food you eat and uses it to manufacture two main hormones, thyroxine (T-4) and triiodothyronine (T-3). These hormones maintain the rate at which your body uses fats and carbohydrates, help control your body temperature, influence your heart rate and regulate the production of protein. Your thyroid gland also produces calcitonin, a hormone that regulates the amount of calcium in your blood.

• Calcium (Calcium citrate)
• Calcium Gluconate)

The thyroid contains two main types of cells. Follicle cells make the thyroid protein thyroglobulin and produce and store thyroxine and triiodothyronine. Other cells, called C cells (parafollicular cells), produce calcitonin. Distinguishing between these cells is important because each can give rise to different types of cancer.

Papillary and follicular cancers develop in follicle cells. They account for the great majority of thyroid cancers, can usually be completely removed with surgery and generally result in an excellent prognosis. Medullary cancer, on the other hand, arises in the thyroid's C cells and is generally more aggressive and harder to treat than papillary and follicular cancers.

Descriptions of the types of thyroid cancer follow:

• Papillary cancer (papillary carcinoma, papillary adenocarcinoma). This is the most common type of thyroid cancer. It develops from thyroid follicle cells and usually appears as a single mass in one lobe of the thyroid. Anyone, including children, can develop papillary cancer, but it's most common in women who are between 30 and 50 years of age. Although most papillary cancers grow slowly, they often spread to the lymph nodes early in the course of the disease. This usually doesn't affect the outlook for recovery, which is generally excellent when the cancer is small and its spread limited to the lymph nodes in your neck. The prognosis isn't as positive for people with very large tumors or in the rare cases when papillary cancer has invaded tissues other than the lymph nodes. But even papillary tumors that have spread to the lungs or bone often can be successfully treated with radioactive iodine (radioiodine).

• Follicular cancer (follicular carcinoma, follicular adenocarcinoma). Follicular tumors don't usually spread to the lymph nodes but are likely to invade the veins and arteries within the thyroid. From there, they may spread to organs such as your lungs and bone.

• Anaplastic cancer (anaplastic carcinoma). This rare form of thyroid cancer is sometimes called undifferentiated cancer because it looks very different from normal thyroid tissue under a microscope. It appears to develop from an existing, undiagnosed papillary or follicular cancer. Anaplastic cancer is extremely aggressive, spreads rapidly to the lymph nodes and trachea, and then to other organs, especially the lungs and bone. For that reason, it's often not curable surgically by the time it's diagnosed. Unfortunately, other therapies, such as radiation, aren't usually successful in controlling anaplastic cancer.

• Medullary cancer (medullary carcinoma). Rather than arising from follicle cells, this type of thyroid cancer develops in calcitonin-producing C cells. Medullary tumors usually make calcitonin along with carcinoembryonic antigen (CEA) — a protein produced by certain cancers. Both are released into the bloodstream and can be detected by blood tests. But in many cases, medullary cancer may spread to the lymph nodes or other organs before a lump is detected or blood tests are performed.

• There are three main types of medullary cancer: sporadic, multiple endocrine neoplasia, type II (MEN 2), and familial. Sporadic tumors make up the great majority of medullary cancers. They primarily affect people between the ages of 40 and 60 and are not inherited.

• MEN 2 medullary cancers, on the other hand, are passed from one generation to the next and usually appear much earlier in life than other thyroid cancers. In addition to thyroid tumors, people with MEN 2 usually have tumors in other endocrine glands, such as the adrenal or parathyroid glands.

• MEN 2 has two subtypes, MEN 2A and MEN 2B. People with MEN 2A often develop adrenal gland tumors (pheochromocytomas) and tumors of the parathyroid glands — four glands that sit behind the thyroid and produce a hormone that helps maintain the proper balance of calcium and phosphorus in the body. Although these associated tumors are usually benign, they can lead to serious complications. Adrenal gland tumors, for example, can cause high blood pressure, while parathyroid tumors can contribute to dangerously high levels of calcium as well as to osteoporosis and kidney stones.

• People with MEN 2B also have adrenal gland tumors, but not parathyroid gland problems. Instead, they develop benign nerve tissue growths (neuromas), mainly on their tongues, the underside of their eyelids and in the intestine. They may also have thick lips and thickened eyelids. The thyroid cancer that occurs in people with MEN 2B syndrome is particularly aggressive and usually develops at a very young age.

• Familial medullary cancers are inherited, but unlike MEN 2 cancers, affect only the thyroid gland. They are usually slower-growing than MEN 2 tumors, and they primarily affect people who are in their 40s and 50s.

• Thyroid lymphoma. This rare type of cancer doesn't develop from thyroid follicular cells or C cells. Instead, it starts in immune system cells called lymphocytes. Although most lymphomas begin in the lymph nodes, some occasionally appear in other organs, such as the thyroid.

What causes thyroid cancer?
Healthy cells grow and divide in an orderly way. This process is controlled by DNA — the genetic material that contains the instructions for every chemical process in your body. When DNA is damaged or altered, changes occur in these instructions. One result is that cells may begin to grow out of control and eventually form a tumor — a mass of malignant cells.

In the case of thyroid cancer, DNA damage can occur from exposure to environmental contaminants such as radiation, from the aging process, or, in medullary cancers, from genetic causes:

• Radiation. This is the cause of most papillary cancers and anaplastic cancers, which may not appear for decades after exposure. Children who received high doses of radiation to treat conditions such as acne, enlarged tonsils and scalp infections between the 1920s and 1950s are at higher risk of thyroid cancer and thyroid nodules than are those who didn't receive these treatments. Also at high risk of thyroid cancer are people who have been exposed to radioactive particles from atomic weapons tests and nuclear power plant accidents such as the 1986 Chernobyl disaster in the former Soviet Union.

• The greatest cancer risk comes from a component of fallout called iodine 131, a radioactive isotope of naturally occurring iodine that concentrates in the thyroid gland. Iodine 131 is especially harmful to children, whose thyroid glands are still developing. In Ukraine and Belarus, the regions most immediately affected by the Chernobyl accident, at least 2,000 cases of thyroid cancer in children and adolescents have been linked to iodine 131. Most children were exposed when they consumed milk, fruits and vegetables contaminated by fallout.

• Genetic causes. Familial medullary cancer and MEN 2 medullary thyroid cancers result from a genetic defect — a mutation of a gene that controls cell growth (oncogene) called RET. The mutation is inherited, and each child of a parent with the defect has a 50 percent chance of inheriting it as well. Before the discovery of the RET gene, people with a family history of medullary thyroid cancer were screened using tests that measure levels of calcitonin and carcinoembryonic antigen. Now, genetic testing allows doctors to discover an inherited tendency to thyroid cancer much earlier — before symptoms ever develop. About 90 percent to 95 percent of people with the RET mutation go on to develop cancer. A few families who don't have the RET genetic defect also develop and pass on medullary thyroid cancer and MEN 2.

• Genetic testing is controversial, especially when a disease can't be prevented or successfully treated. But medullary thyroid cancer can be prevented by surgically removing the thyroid gland (thyroidectomy) before problems occur. Children at risk of MEN 2A may have this surgery around age 7 or 8 and children at risk of MEN 2B as early as 1 year of age. You can live a normal life without a thyroid gland, although you must take thyroid hormones for life to replace those your thyroid would ordinarily produce. And because MEN 2 is a syndrome involving other types of tumors, children who have their thyroid glands removed still need to be monitored for other potential problems.

• If you have a family history of medullary thyroid cancer, consider talking to a genetic counselor. He or she can explain the advantages and disadvantages of genetic testing and the risks and benefits of thyroid surgery.

Thyroid cancer > next > 1 > 2 > 3 > 4

Related Sites:

Dr. Eddy's Clinic Integrated Medicine - Web Journal
Articles Forum - Forum Integrated Medicine - Ayurvedic Forum
Ayurvedic	Disease	Men Health	Treatment
Aging	Vaccination	Women Health	Integrated Medicine
Submit a Article