What is a Thyroid Nodule?
The term thyroid nodule refers to any abnormal growth of thyroid cells within the thyroid. Most thyroid nodules do not cause any symptoms. They may be discovered during a routine physical examination, you might notice a lump in your neck while looking in a mirror, or they may be discovered incidentally during a radiological procedure. A few patients with thyroid nodules may complain of pain in the neck, jaw, or ear. If the nodule is large enough, it may cause difficulty swallowing or cause a “tickle in the throat” or shortness of breath if it is pressing on the windpipe. Rarely, hoarseness can be caused if the nodule irritates a nerve to the voice box.
Thyroid nodules are extremely common. The chances are 1 in 10 that you or someone you know will develop a thyroid nodule. Although thyroid cancer is the most important concern of the thyroid nodule, fortunately it occurs in less than 10% of nodules. This means that about 9 of 10 nodules are benign (noncancerous). The most common types of noncancerous thyroid nodules are known as colloid nodules and follicular neoplasms. If a nodule produces thyroid hormone without regard to the body’s need, it is called an autonomous nodule, and it can occasionally lead to hyperthyroidism. If the nodule is filled with fluid or blood, it is called a thyroid cyst.
We do not know what causes most noncancerous thyroid nodules to form. A patient with hypothyroidism may also have a thyroid nodule, particularly if the cause is the inflammation known as Hashimoto’s thyroiditis. Sometimes a lack of iodine in the diet can cause a thyroid gland to produce nodules. Some autonomous nodules have a genetic defect that causes them to grow.
Once the nodule is discovered, your doctor will try to determine whether the lump is the only problem with your thyroid or whether the entire thyroid gland has been affected by a more general condition such as hyperthyroidism or hypothyroidism. Your physician will examine the thyroid to see whether the entire gland is enlarged, whether there is a single nodule present, or whether there are many lumps or nodules in your thyroid. The initial laboratory tests may include blood tests to measure the amount of thyroid hormone (thyroxine, or T4) and thyroid-stimulating hormone (TSH) in your blood to determine whether your thyroid is functioning normally. Most patients with thyroid nodules will also have normal thyroid function tests. Rarely is it possible to determine whether a thyroid nodule is cancerous by physical examination and blood tests alone, and so the evaluation of the thyroid nodule often includes specialized tests such as a thyroid fine needle biopsy, a thyroid scan, and/or a thyroid ultrasound.
What is a thyroid fine needle aspiration?
A fine needle aspiration (otherwise called a biopsy) of a thyroid nodule is a procedure that is the best way to assess this nodule. It is reliable, fast, safe, and causes only minimal discomfort. If you have any questions or concerns, you are encouraged to contact us immediately prior to your scheduled procedure day.
Why do I need a biopsy?
While the great majority of lumps are not malignant, the treatment of the nodule will depend upon its exact nature. Fine needle aspiration is a simple biopsy procedure that can provide the necessary information on which to guide your treatment. About 90 percent of the time, biopsy results can determine the exact nature of the nodule so that the correct treatment can be determined. However, in 5 percent of cases, it is not possible to obtain enough tissue from a particular nodule. If there is insufficient material, we will need to repeat the biopsy.
Are there alternatives?
Yes, however they are much more invasive and require obtaining a tissue diagnosis through a surgical biopsy. This surgical procedure is also highly reliable, but can involve discomfort, major expense, and several risks, such as bleeding, infection, and scarring. Fine needle aspiration, on the other hand, and in most cases, can accurately determine the nature of the lump more safely and comfortably than surgical biopsy.
How is the biopsy performed?
After cleansing the skin on the neck, which overlies the thyroid, a very small needle is passed through the skin and into the nodule. The needle is less than 1 mm. in diameter and is smaller than the needles used to draw blood from the arm. During the procedure, you may briefly feel discomfort similar to that encountered when a technician draws blood from your arm. The biopsy takes only a few seconds to perform. Normally, two passes of the nodule are taken during your visit. The cells will immediately be assessed to determine if there are enough thyroid cells to be sent to make a diagnosis. If they are determined to be “adequate” the procedure is done. However, if they are determined to be “inadequate” one or two more passes may be required. After the biopsy, you will be able to drive, return to work, or perform any other activity that you normally do. Continue taking any medicine your doctors have given you as directed since the biopsy does not affect medication schedules; nor does medication affect the biopsy results. Please inform the doctor if you are taking Coumadin / Warfarin.
What are the risks associated with fine needle aspiration biopsy?
Fine needle aspiration poses no significant risk to you. Some patients report a mild, dull, throbbing sensation in the area of the biopsy, which usually subsides within 30 to 60 minutes. This minor discomfort does not bother most patients and requires no medication. If you experience any soreness in the area, simply apply an ice pack and take Tylenol. Some patients have expressed concern that passage of a needle through a tumor might cause the tumor to spread. This concern has been examined by physicians at several universities and such tumor spread has never been reported. You may experience some discomfort for several days following the procedure. This is normal. If you are concerned about excessive discomfort, redness, swelling or signs of infection – call our office immediately.
How long does it take to obtain the results of the fine needle aspiration biopsy?
Following the procedure, you will schedule a follow up appointment to discuss the results and possible treatment options. Dr. Metchick does not give results over the phone. This appointment will usually be scheduled for the week following the procedure.
Hyperthyroidism and Radioactive Iodine
How is Hyperthyroidism Treated?
There is no single treatment that is best for all patients with hyperthyroidism. There are various treatments which will be influenced by your age, the type of hyperthyroidism that you have, the severity of your hyperthyroidism, and other medical conditions that may be affecting your health.
Another way to treat hyperthyroidism is to destroy the thyroid cells that make thyroid hormone. Because these cells need iodine to make thyroid hormone, they will take up any form of iodine in your blood stream, whether it is radioactive or not. The radioactive iodine used in this treatment is administered by mouth, usually in a small capsule that is taken just once. Once swallowed, the radioiodine gets into your blood stream and quickly is taken up by the overactive thyroid cells. The radioiodine that is not taken up by the thyroid cells disappears from the body within days. It is either eliminated in the urine or transformed by radioactive decay into a nonradioactive state. Because of the elimination from the body there are precautions that need to be taken to prevent others from being affected by the radioactive iodine. Over a period of several weeks to several months (during which time drug treatment may be used to control hyperthyroid symptoms), radioactive iodine damages the cells that have taken it up. The result is that the thyroid or thyroid nodules shrink in size, and the level of thyroid hormone in the blood returns to normal. Sometimes patients will remain hyperthyroid, but usually to a lesser degree than before. For them, a second radioiodine treatment can be given if needed. More often, hypothyroidism (an underactive thyroid) occurs after a few months. In fact, most patients treated with radioactive iodine will become hypothyroid after a period of several months to many years. Hypothyroidism can easily be treated with a thyroid hormone supplement taken once a day.
Radioactive iodine has been used to treat patients for hyperthyroidism for over 60 years. Because of concern that the radioactive iodine might somehow damage other cells in the body, produce cancer, or have other long-term unwanted effects such as infertility or birth defects, the physicians who first used radioiodine treatments were careful to treat only adults and to observe them carefully for the rest of their lives. Fortunately, no complications from radioiodine treatment have become apparent over many decades of careful follow-up of patients. As a result, in the United States more than 70% of adults who develop hyperthyroidism are treated with radioactive iodine. More and more children are also being treated with radioiodine.
A rarer (occurring in 1 of 500 patients), but more serious side effect is a decrease in the number of white blood cells. Such a decrease can lower your resistance to infection. Very rarely, these white blood cells disappear completely, producing a condition known as agranulocytosis, a potentially fatal problem if a serious infection occurs. If you are taking one of these drugs and get an infection such as a fever or sore throat, you should stop the drug immediately and have a white blood cell count that day. Even if the drug has lowered your white blood cell count, the count will return to normal if the drug is stopped immediately. But if you continue to take one of these drugs in spite of a low white blood cell count, there is a risk of a more serious, even life-threatening infection. Liver damage is another very rare side effect. You should stop the drug and call your doctor if you develop yellow eyes, dark urine, severe fatigue, or abdominal pain.
Drugs known as antithyroid agents—methimazole (Tapazole®) or propylthiouracil (PTU)—may be prescribed to treat the hyperthyroidism by blocking the thyroid gland’s ability to make new thyroid hormone. These drugs work well to control the overactive thyroid, bring prompt control of hyperthyroidism, and do not cause permanent damage to the thyroid gland. In about 20% of patients with Graves’ disease, treatment with antithyroid drugs for a period of 12 to 18 months will result in prolonged remission of the disease. For patients with toxic nodular or multinodular goiter, antithyroid drugs are used in preparation for either radioiodine treatment or surgery. Antithyroid drugs cause allergic reactions in about 5% of patients who take them. Common minor reactions are red skin rashes, hives, and occasionally fever and joint pains.
Your hyperthyroidism can be permanently cured by surgical removal of most of your thyroid gland. This procedure is best performed by a surgeon who has much experience in thyroid surgery. An operation could be risky unless your hyperthyroidism is first controlled by an antithyroid drug (see above) or a beta-blocking drug (see below). Although any surgery is risky, major complications of thyroid surgery occur in less than 1% of patients operated on by an experienced thyroid surgeon. These complications include damage to the parathyroid glands that surround the thyroid and control your body’s calcium levels (causing problems with low calcium levels) and damage to the nerves that control your vocal cords (causing you to have a hoarse voice).
After your thyroid gland is removed, the source of your hyperthyroidism is gone and you will likely become hypothyroid. As with hypothyroidism that develops after radioiodine treatment, your thyroid hormone levels can be restored to normal by treatment once a day with a thyroid hormone supplement.
No matter which of these three methods of treatment you have for your hyperthyroidism, your physician may prescribe a class of drugs known as the beta adrenergic blocking agents that block the action of thyroid hormone in your body. They usually make you feel better within hours, even though they do not change the high levels of thyroid hormone in your blood. These drugs may be extremely helpful in slowing down your heart rate and reducing the symptoms of palpitations, shakes, and nervousness until one of the other forms of treatment has a chance to take effect. Propranolol (Inderal®) was the first of these drugs to be developed. Some physicians now prefer related, but longer-acting betablocking drugs such as atenolol (Tenormin®), metoprolol (Lopressor®) and nadolol (Corgard®), and Inderal-LA® because of their more convenient once- or twice-a-day dosage.
Radioactive iodine therapy
A major reason for the usually excellent prognosis for patients with papillary and follicular thyroid cancer is that radioactive iodine can be used to seek out and destroy thyroid cancer cells with little or no damage to other tissues in the body. Thyroid cells normally concentrate iodine from the bloodstream to use to produce the thyroid hormones. By contrast, thyroid cancer cells usually take up only tiny amounts of iodine. However, high levels of thyroid stimulating hormone (TSH) can arouse thyroid cancer cells to take up significant amounts of iodine.
If your doctor recommends radioactive iodine therapy, high levels of TSH will be produced in your body there by making you hypothyroid for a short time—either by not starting thyroid hormone pills after the thyroid gland is removed or by stopping your thyroid hormone pills if you are already on medication. Sometimes, there are ways to minimize your symptoms of hypothyroidism while you are becoming hypothyroid. Also, you may be asked to go on a low iodine diet before the treatment to increase the effectiveness of the radioactive iodine. Once the TSH level is high enough, a whole body iodine scan is done by administering a small dose of radioactive iodine to determine if there are remaining thyroid cells that need to be destroyed. If enough cells show up on the whole-body iodine scan, a large dose of radioactive iodine (I-131) is given, and then the thyroid pills are re-started. Radioactive iodine therapy has proved to be safe and well-tolerated, and it has even been able to cure cases of thyroid cancer that had already spread to the lungs.
What is the follow-up for patients with thyroid cancer?
Periodic follow-up examinations are essential for all patients with thyroid cancer because the thyroid cancer can return—sometimes many years after the apparently successful initial treatment. These follow-up visits include a careful history and physical examination, with particular attention to the neck area, as well as blood tests to determine if any changes of your thyroid hormone dose are needed. In particular, blood tests are done to measure the levels of T4 and TSH as well as a thyroid cell protein, thyroglobulin, which serves as a thyroid cancer marker. The thyroid hormone dose is adjusted to lower the TSH level into the low range. If the thyroglobulin level is still detectable despite a TSH in the low range, it means that there still are potential thyroid cancer cells functioning in the body. This finding may lead to additional tests and possible further treatment with radioactive iodine and/or surgery. Unfortunately, in some thyroid cancer patients the presence of interfering antibodies in the blood may prevent accurate thyroglobulin measurement. In addition to routine blood tests, your doctor may want to repeat periodically a thyroid ultrasound to determine if any thyroid tissue remains.
What is the treatment for thyroid cancer?
The primary therapy for all forms of thyroid cancer is surgery. The generally accepted approach is to remove the entire thyroid gland, or as much of it as can be safely removed. After surgery, patients need to be on thyroid hormone for the rest of their life. Often the thyroid cancer is cured by surgery alone, especially if the cancer is small. If the cancer is large within the thyroid or if it has spread to lymph nodes or if your doctor feels that you are at high risk for recurrent cancer, radioactive iodine can be used to destroy thyroid cancer cells after removal of the thyroid gland by surgery.
The Low-Iodine Diet
- (Adapted from Thyroid Cancer Survivor’s Association)
Thyroid cancer patients with papillary or follicular thyroid cancer often receive a dose of radioactive iodine (RAI) about two months after their surgery in an attempt to destroy (ablate) any remaining thyroid cells in their bodies. Most thyroid cancer patients also undergo whole-body radioiodine scans at periodic intervals, using a “tracer” dose of RAI. If their scan is not “clean”, they then receive treatment with a larger dose of RAI in an attempt to destroy any remaining thyroid cells in their bodies.
In preparation for an RAI scan or an RAI treatment, patients are usually asked to go on a low-iodine diet. The purpose of a low-iodine diet is to deplete the body of its natural stores of iodine to help make the radioactive iodine treatment more effective. The premise is that when the radioactive iodine is administered, the thyroid cells will “suck” up the iodine because it has been so depleted.
This diet is for a short period. The usual time period is around two weeks or slightly more. The diet usually begins around two weeks before testing and continues through the testing and treatment period. However, recommendations for the time period can vary, depending partly on the individual patient’s circumstances.
Remember: LOW IODINE has NOTHING TO DO WITH SODIUM. Sodium in any form is OK, as long as it is not provided as IODIZED salt. NON-IODIZED salt is OK for the diet, as long as it is not sea salt. As noted below, you should avoid any product or ingredient from the sea. That's because sea-based products are high in iodine. Also, this is a "low-iodine" diet, not a "no-iodine" diet.
Avoid These Foods and Additives
Avoid the following foods, starting when instructed before your radioactive iodine test or treatment, and continue as instructed until after your radioactive iodine treatment is completed. These foods and ingredients are high in iodine (over 20 mcg per serving, according to researchers' presentations at our conferences).
• Iodized salt and sea salt and any foods containing iodized salt or sea salt. Non-iodized salt (such as Kosher salt unless the label says that it is iodized or sea salt) may be used. The reason to avoid sea salt is that all products from the ocean tend to be high in iodine. You can usually find plain, non-iodized salt next to the iodized salt at your grocer.
• Seafood and sea products (fish, shellfish, seaweed, seaweed tablets, kelp). These are all very high in iodine and should be avoided.
• Dairy products (milk, cheese, cream, yogurt, butter, ice cream, powdered dairy creamers, other dairy products). Although the source of the iodine is not known, tests of all types of dairy products have generally shown the presence of iodine, sometimes in very large quantities. Animals secrete dietary iodine into their milk, animal feeds often contain iodine, and products containing iodine may be used to clean udders. Also, methods for processing dairy products can change over time and from one company to another. Note: Nondairy creamers often have iodine-containing ingredients.
• Egg yolks or whole eggs or foods containing whole eggs. (Egg whites are acceptable, because they do not contain iodine).
• Foods or products that contain these additives: carrageen, agar-agar, algin, alginate, nori (these are food additives that are seaweed by-products).
• Commercial bakery products. Avoid bread products that contain iodine/iodate dough conditioners (usually small bakery breads are safe; it’s best to bake it yourself or substitute with Matzos). If you read labels closely, you may also be able to find crackers made only with flour and water. While a few commercial bakery products have tested low in iodine, manufacturing processes can change over time.
• Red Dye #3. However, Red Dye #40 is OK. We suggest that you avoid red, orange, or brown processed food, pills, and capsules. Many red, red-orange, and brown food dyes contain iodine and should be avoided. The problem with food colors is specific to Red Dye FD&C #3 (erythrosine) ONLY. However, the problem is that some food labels do not specify which red dyes are used. Better safe than sorry. For medications, the best source is the Physician’s Desk Reference (PDR), which clearly states the ingredients. For example, Rocaltrol in the 0.5 mcg size is NOT good for the diet because it contains FD&C Red Dye # 3. However, Rocaltrol 0.25 mcg does not and is safe for the diet (you can take two of them to get to the 0.5 mcg dose). Please always check with your physician.
• Chocolate (for its milk content). Cocoa powder and some dark chocolates are permitted. Check the label for other ingredients not allowed on the low-iodine diet.
• Molasses (sulfured, such as blackstrap molasses, which has a slightly bitter taste. It's okay to use the milder, fairly sweet unsulfured molasses usually used in cooking.)
• Soy products (soy sauce, soy milk, tofu). These vary in iodine content. Some are moderate in iodine. (Some diets say that vegetable oil with soy is okay.)
• Some beans – The National Institutes of Health diet says to avoid these beans: red kidney beans, lima beans, navy beans, pinto beans, and cowpeas.
• Potato skins. These have iodine. The inside of the potato is fine.
• Iodine-Containing Vitamins, and Food Supplements, also products containing iodate or iodide. Check the label and ingredients and discontinue completely if iodine is included. Most vitamins with minerals contain iodine. Vicon Forte, a multivitamin, is fine for the diet.
• If you are taking a Medication that contains iodine, check with your physician.
During your time on the low-iodine diet, avoid foods high in iodine (over 20 mcg per serving) and limit foods moderate in iodine (5 to 20 mcg per serving). You may freely eat any foods that are low in iodine (up to 5 mcg per serving). There are lots of foods that you can eat. We will include a list in these guidelines. For recipes and a snack list, use ThyCa’s free Low Iodine Cookbook. You can download it free from www.thyca.org and print it out. You also can adapt your favorite recipes from your own cookbooks to the low-iodine diet by eliminating ingredients that are high in iodine, or by substituting ingredients from the list of foods and ingredients that are fine on the diet. Thyroid cancer survivors created this cookbook and donated these recipes to help you with this diet.
What About Restaurant Foods and Fast Food?
Although restaurants generally use non-iodized salt, it is not possible to know whether a particular restaurant is using iodized salt or sea salt. The manager or serving staff may not know what product is being used, or whether butter or other dairy products are present in foods. The ingredients that chain and fast-food restaurants use may change.
Therefore, we suggest that you try to avoid restaurant foods, as there is no reasonable way to determine which restaurants use iodized salt. Avoid if in doubt.
What About Manufactured and Processed Foods?
Some published low-iodine diets allow salty processed foods. Some of these foods include potato chips and cured and corned foods such as hot dogs, ham, corned beef, sauerkraut, bacon, sausage, and salami.
Currently, manufacturers of processed foods generally use non-iodized salt. However, food processing techniques can change and labels are not always accurate or up to date. For that reason, if fresh foods are available in their area, many patients prefer to eat fresh foods rather than processed foods during the short period of being on the low-iodine diet. They avoid processed food, because it is not known for sure whether or not iodized salt has been used. For any processed food, it is also important to read the label to be sure there is no Red Dye #3.
In the past many patients have contacted manufacturers asking whether or not they used iodized salt in their products. Doing this is NOT recommended for the following reasons:
1. Manufacturers cannot guarantee that the ingredients they receive from their suppliers do not contain iodized salt.
2. Manufacturers often use iodine-base cleaners on their machinery.
3. Because fewer and fewer manufacturers have been using iodized salt in their food processing, there seems to be a rise in the number of goiter cases. It might become the practice to start using iodized salt again.
Foods That Are Fine to Eat on the Low-Iodine Diet
The low-iodine diet consists mostly of fresh, low-fat, low-calorie foods. Because of this, following this diet greatly reduces the tendency to gain weight while hypothyroid. The following are fine. Their iodine content is 5 mcg or less, according to the researchers' presentations at our conferences.
• Fresh fruits and fruit juices, except rhubarb, maraschino cherries (if contain Red Dye #3), and fruit cocktail.
• Vegetables, raw and fresh-cooked and frozen without salt.
(But not certain beans [pinto, lima, navy, red kidney, cowpeas], soy products, and skins of potatoes).
• Unsalted nuts and unsalted nut butters.
• Moderate amounts of grain/cereal products (see above) and fresh chicken, beef, and other meats (see above).
• Sugar, jelly, honey, maple syrup.
• Black pepper, fresh or dried herbs.
• Oils and salad dressings provided they contain only allowed ingredients.
(Some diets say that soybean oil is okay; others say to avoid all soy products.)
• Homemade foods
• Cola, diet cola, lemonade, sodas (except those with Red Dye #3), non-instant coffee and tea, beer, wine, other alcohol.
Food prepared from any fresh meats, fresh poultry, fresh or frozen vegetables, and fresh fruits should be fine for this diet,
provided that you do not add any of the iodine-containing ingredients listed above to avoid.
• Fresh fruit (not canned)—apples, grapes, bananas, melon, etc. (keep on hand and ready to eat)
• Apple sauce (preferably in a glass jar—check label to be sure no salt)
• Raisins and other dried fruits
• Raw carrot sticks (chopped and ready to eat)
• Unsalted peanut butter (great with apple slices, carrot sticks, crackers and rice cakes). Unsalted peanut butter tends to be the “natural” type that separates so that the top is swimming in oil, while the bottom is dry. Dump the contents into a bowl and stir until the oil is evenly distributed. (Add non-iodized salt to taste, if desired.) Spoon back into jar and refrigerate. Chilled, the product does not separate, yet it is still easy to spread.
• Unsalted Matzo crackers (in the Kosher aisle)
• Unsalted rice cakes
• Popcorn (homemade, with non-soybean oil and non-iodized salt)
• Unsalted nuts—pecans, walnuts, almonds, etc. (shop for these in the baking supplies aisle, since nuts in the snack foods aisle will be salted)
• Homemade bread or muffins (made with a low-iodine recipe) with honey or jelly (check label to be sure no Red Dye #3)
• Sodas, including colas, 7-Up, and Sprite (bottles are preferable to cans; read labels, as caramel-colored sodas may have Red Dye #3)
• Sorbet (check label to be sure no salt, dairy, or Red Dye #3.)
DISCLAIMER—Do not assume that all items on this list are low iodine in every form or merchandise brand. It is each person’s responsibility to read labels to be sure items meet the requirements of his/her particular version of the low-iodine diet.
Limit the Amounts of these Foods
The following foods are moderate in iodine, so you can eat them but should limit your intake. Moderate in iodine means 5 to 20 mcg per serving, according to the researchers' presentations at our conferences.
• Up to 5 ounces per day of fresh meats such as chicken, beef, pork, lamb, and veal are fine on the low-iodine diet. (Up to 6 ounces, according to one of the research presentations.) Whole cuts tend to contain less iodine than do ground meats. Also, check the label on whole turkeys, turkey breasts, turkey cutlets, chicken, and all pork products. Many food makers inject broths into the turkey or chicken or pork. The label may not indicate whether the broth contains iodized salt. If you are not sure, go to your local butcher for fresh turkey, pork, or chicken.
• Up to 4 servings per day of grains, cereals, pasta, and breads without iodine-containing ingredients are fine on this diet. Homemade baked goods and cereals are best on this diet. If you use processed foods, read the labels carefully to avoid iodine-containing ingredients. Also, remember that labels are not always accurate or up to date.
• Rice's vary in the amount of iodine, so rice should be eaten only in limited amounts. Some low-iodine diets recommend avoiding rice. Basmati rice is the best to eat on the low-iodine diet.
Lee N. Metchick, M.D. F.A.C.E Specialized in Endocrinology, Diabetes and Metabolism
WHAT IS HYPOTHYROIDISM?
Hypothyroidism is an underactive thyroid gland. Hypothyroidism means that the thyroid gland can’t make enough thyroid hormone to keep the body running normally. People are hypothyroid if they have too little thyroid hormone in the blood. Common causes are autoimmune disease, surgical removal of the thyroid, and radiation treatment.
What are the symptoms?
When thyroid hormone levels are too low, the body’s cells can’t get enough thyroid hormone and the body’s processes start slowing down. As the body slows, you may notice that you feel colder, you tire more easily, your skin is getting drier, you’re becoming forgetful and depressed, and you’ve started getting constipated. Because the symptoms are so variable and non-specific, the only way to know for sure whether you have hypothyroidism is with a simple blood test for TSH.
KEEPING OTHER PEOPLE INFORMED
Tell your family members. Because thyroid disease runs in families, you should explain your hypothyroidism to your relatives and encourage them to get regular TSH tests. Tell your other doctors and your pharmacist about your hypothyroidism and the drug and dose with which it is being treated. If you start seeing a new doctor, tell the doctor that you have hypothyroidism and you need your TSH tested every year. If you are seeing an endocrinologist, ask that copies of your reports be sent to your primary care doctor.
WHAT CAN YOU EXPECT OVER THE LONG TERM?
There is no cure for hypothyroidism, and most patients have it for life. There are exceptions: many patients with viral thyroiditis have their thyroid function return to normal, as do some patients with thyroiditis after pregnancy.
Hypothyroidism may become more or less severe, and your dose of thyroxine may need to change over time. You have to make a lifetime commitment to treatment. But if you take your pills every day and work with your doctor to get and keep your thyroxine dose right, you should be able to keep your hypothyroidism completely controlled throughout your life. Your symptoms should disappear and the serious effects of low thyroid hormone should stop getting worse and should actually improve. If you keep your hypothyroidism well-controlled, it will not shorten your life span.
What causes hypothyroidism?
There can be many reasons why the cells in the thyroid gland can’t make enough thyroid hormone. Here are the major causes, from the most to the least common.
In some people’s bodies, the immune system that protects the body from invading infections can mistake thyroid gland cells and their enzymes for invaders and can attack them. Then there aren’t enough thyroid cells and enzymes left to make enough thyroid hormone. This is more common in women than men. Autoimmune thyroiditis can begin suddenly or it can develop slowly over years. The most common forms are Hashimoto’s thyroiditis and atrophic thyroiditis.
Surgical removal of part or all of the thyroid gland. Some people with thyroid nodules, thyroid cancer, or Graves’ disease need to have part or all of their thyroid removed. If the whole thyroid is removed, people will definitely become hypothyroid. If part of the gland is left, it may be able to make enough thyroid hormone to keep blood levels normal.
Some people with Graves’ disease, nodular goiter, or thyroid cancer are treated with radioactive iodine (I-131) for the purpose of destroying their thyroid gland. Patients with Hodgkin’s disease, lymphoma, or cancers of the head or neck are treated with radiation. All these patients can lose part or all of their thyroid function.
◾Congenital hypothyroidism (hypothyroidism that a baby is born with). A few babies are born without a thyroid or with only a partly formed one. A few have part or all of their thyroid in the wrong place (ectopic thyroid). In some babies, the thyroid cells or their enzymes don’t work right.
Thyroiditis is an inflammation of the thyroid gland, usually caused by an autoimmune attack or by a viral infection. Thyroiditis can make the thyroid dump its whole supply of stored thyroid hormone into the blood at once, causing brief hyperthyroidism (too much thyroid activity); then the thyroid becomes underactive.
◾Medicines. Medicines such as amiodarone, lithium, interferon alpha, and interleukin-2 can prevent the thyroid gland from being able to make hormone normally. These drugs are most likely to trigger hypothyroidism in patients who have a genetic tendency to autoimmune thyroid disease.
Too much or too little iodine. The thyroid gland must have iodine to make thyroid hormone. Iodine comes into the body in food and travels through the blood to the thyroid. Keeping thyroid hormone production in balance requires the right amount of iodine. Taking in too much iodine can cause or worsen hypothyroidism.
Damage to the pituitary gland. The pituitary, the “master gland,” tells the thyroid how much hormone to make. When the pituitary is damaged by a tumor, radiation, or surgery, it may no longer be able to give the thyroid instructions and the thyroid may stop making enough hormone.
Rare disorders that infiltrate the thyroid. In a few people, diseases deposit abnormal substances in the thyroid and impair its ability to function. For example, amyloidosis can deposit amyloid protein, sarcoidosis can deposit granulomas, and hemochromatosis can deposit iron.
How is hypothyroidism treated?
Thyroxine (T4) replacement.
Hypothyroidism can’t be cured. But in almost every patient, hypothyroidism can be completely controlled. It is treated by replacing the amount of hormone that your own thyroid can no longer make, to bring your T4 and TSH back to normal levels. So even if your thyroid gland can’t work right, T4 replacement can restore your body’s thyroid hormone levels and your body’s function. Synthetic thyroxine pills contain hormone exactly like the T4 that the thyroid gland itself makes. All hypothyroid patients except those with severe myxedema (life-threatening hypothyroidism) can be treated as outpatients, not having to be admitted to the hospital.
Side effects and complications. The only dangers of thyroxine are caused by taking too little or too much. If you take too little, your hypothyroidism will continue. If you take too much, you’ll develop the symptoms of hyperthyroidism— an overactive thyroid gland. The most common symptoms of too much thyroid hormone are fatigue but inability to sleep, greater appetite, nervousness, shakiness, feeling hot when other people are cold, and trouble exercising because of weak muscles, shortness of breath , and a racing, skipping heart. Patients who have hyperthyroid symptoms at any time during thyroxine replacement therapy should have their TSH tested. If it is low, indicating too much thyroid hormone, their dose needs to be lowered.
1.Biopsies performed almost 2000
2. Biopsies performed annually about 250
3. Non-diagnostic rate <1%
4. Benign nodules about 85%
5. Malignant Nodule <5%
6. Thyroid ultrasounds performed monthly about 200
Lee N. Metchick, M.D. F.A.C.E
Thyroid Institute of Central Florida