The thyroid gland is the largest gland in the neck. It is butterfly-shaped and has two lobes (one on each side of the neck). The entire structure is about two inches long, located just below the Adam's apple. Glands are endocrine and exocrine. Because the thyroid works by secreting hormones directly into the bloodstream, it is considered our main endocrine gland and a key part of the entire endocrine system. The thyroid gland needs iodine to function, which it uses to make the thyroid hormones thyroxine (T4) and triiodothyronine (T3).
The thyroid gland can store these hormones for later use because they will be released when needed. These hormones can then target cells in the blood. As already mentioned, the thyroid gland is located at the front of the neck, in front of our trachea. A closer look at the structure of the thyroid gland reveals that it is reddish-brown in color. The color is because the thyroid gland is highly innervated and supplied with blood from the superior and inferior thyroid arteries and the external carotid arteries. The two-lobed structure is connected by a bridge called the isthmus, which is located in the middle of the lobes. The location of the thyroid gland is relatively easy to visualize because it is an area that is regularly inspected during doctor visits. Of course, a normal-sized gland will not be felt and becomes noticeable only when the gland is swollen or nodules appear. Thyroid functions. The thyroid gland really stands out for its versatile functions. She plays the main role controlling our body's metabolism. The simplest way to define metabolism is our body's ability to convert food into energy. In addition, the thyroid gland secretes hormones that regulate our vital functions and maintain internal homeostasis. Among the most common primitive bodily functions it controls are our breathing and heart rate. Our weight is also monitored by the thyroid gland, which explains why patients with an impaired thyroid gland can fluctuate wildly in weight. Even our internal body temperature and cholesterol levels will be fine-tuned by thyroid hormones. The wings or lobes of the thyroid gland have a distinct function. Their function is to synthesize thyroid hormones. They can have a wide range of effects that affect almost every tissue in the body through the endocrine channel. At the cellular level, thyroid hormones can increase cellular (metabolic) activity. This affects not only our metabolism, but also protein synthesis. This, of course, facilitates normal development, since growth depends on the constant creation of proteins. Thyroid diseases. The following main thyroid diseases are distinguished: Hyperthyroidism (when the thyroid gland produces too many hormones); Hypothyroidism (when the thyroid gland produces too few hormones); Goiter or otherwise known as goiter; Thyroid nodules; Thyroid cancer. Thyroid cancer Thyroid cancer risk and causes. A person's risk of developing thyroid cancer depends on many factors, including age, certain non-cancerous thyroid conditions, and a family history of thyroid cancer. Several factors are known to increase your risk of developing the disease. Having any of these risk factors does not mean you will definitely get thyroid cancer. Age and gender. Women develop thyroid cancer more often than men and more often in reproductive age. Most women diagnosed with thyroid cancer are between the ages of 44 and 49. In men, thyroid cancer occurs more often at an older age. For example, from 80 to 84 years of age. The causes of thyroid cancer are still not completely clear. Researchers are investigating the relationship between thyroid cancer and pregnancy, oral contraceptive use, hormone replacement therapy, age, and menopause. Severe overweight (obesity). The risk of thyroid cancer is higher in people who are overweight or obese (those who are above normal weight). Non-cancerous (benign) thyroid disease. Some non-cancerous (benign) thyroid conditions increase the risk of thyroid cancer. These include goiter (also called a "goiter"), Hashimoto's disease (a condition where the immune system attacks the thyroid gland), and thyroid nodules (adenomas). It is important to remember that although a lump or nodule increases the risk, thyroid cancer is rare. Thyroid lumps are common. However, only about 5 in 100 people with thyroid nodules are diagnosed with cancer. Family history (heredity). If you have a close family member with thyroid cancer, you have a higher risk of developing thyroid cancer. This risk is higher than the general population if you have one or more first-degree relatives. First degree relatives are parents, brother, sister, son or daughter. However, it is worth remembering that this risk is still very low, since thyroid cancer is rare. Radiation. The thyroid gland is sensitive to radiation. People who have received a lot of radiation may develop thyroid nodules after several years. A thyroid nodule does not always mean that it is cancer. However, you should always consult your doctor if you find nodules. Thyroid cancer is more common in people treated with radiotherapy in childhood. Cancer can develop after several years. Studies have shown that there is no increased risk of thyroid cancer in people who are regularly exposed to radiation at work. Thyroid cancer may be more common in survivors of nuclear explosions or accidents. After the Chernobyl nuclear reactor accident, the incidence of thyroid cancer in Ukraine has increased, especially among children or teenagers. People with low levels of iodine in their bodies may have a higher risk of thyroid cancer after exposure to radiation than people with normal levels of iodine. Systemic lupus erythematosus. It is an autoimmune disease. Studies show that the risk of thyroid cancer in people with systemic lupus erythematosus is about 2 times higher than in the general population. Thyroid cancer is relatively rare compared to other cancers. It is estimated that in 2021 In the United States, approximately 44,000 people will receive a new diagnosis of thyroid cancer, compared to more than 280,000 for breast cancer and more than 150,000 for colon cancer. But despite this, approximately 2,000 patients die from thyroid cancer every year. In 2018, the most recent year for which statistics are available, nearly 900,000 patients in the United States were living with thyroid cancer. Thyroid cancer is usually curable and often cured with surgery and radioactive iodine. Even when thyroid cancer is more advanced, the most common forms of thyroid cancer can be treated effectively. Although a cancer diagnosis is terrifying, most patients with papillary and follicular thyroid cancer have an excellent prognosis. Types of thyroid cancer PAPILARY THYROID CANCER. Papillary thyroid cancer is the most common type, accounting for about 70-80% of all thyroid cancers. Papillary thyroid cancer can occur at any age. It tends to grow slowly and often spreads to the lymph nodes in the neck. Papillary cancer usually has an excellent outlook, even if it has spread to the lymph nodes. FOLLICULAR THYROID CANCER. Follicular thyroid cancer accounts for about 10-15% of all thyroid cancers in the United States. Follicular cancer can spread through the blood to distant organs, especially the lungs and bones. Papillary and follicular thyroid cancer are also known as well-differentiated thyroid cancer (DTC). MEDULLARY THYROID CANCER. Medullary thyroid cancer (MTC) accounts for approximately 2% of all thyroid cancers. For family members of an affected individual, testing for a genetic mutation in the RET proto-oncogene can lead to early diagnosis of medullary thyroid cancer and subsequent curative surgery. 75% of patients with medullary thyroid cancer do not have a hereditary form. ANAPLASTIC THYROID CANCER. Anaplastic thyroid cancer is the most advanced and aggressive form of thyroid cancer and the least responsive to treatment. Anaplastic thyroid cancer is very rare and occurs in less than 2% of thyroid cancer patients. Symptoms of thyroid cancer. Thyroid cancer often presents as a nodule or multiple nodules in the thyroid gland and usually does not cause any other symptoms. Blood tests are not usually helpful in detecting thyroid cancer, and thyroid hormone tests are usually normal even if cancer is present. A neck exam by your doctor is a common way to detect thyroid nodules and thyroid cancer. Often, thyroid nodules are found incidentally during imaging tests such as CT scans and ultrasounds of the neck for completely unrelated reasons. You may have found a thyroid nodule when you notice a lump in your neck while looking in the mirror, wearing a collar or wearing a necklace. Rarely, thyroid cancer and nodules can cause symptoms. You may complain of neck, jaw or ear pain. If the nodule is large enough to compress your windpipe or esophagus, it can make it difficult to breathe, swallow, or cause a "tickling" sensation in your throat. Even more rarely, hoarseness can occur if thyroid cancer invades the nerve that controls your vocal cords. Cancers that occur in thyroid nodules usually do not cause symptoms, and thyroid function tests are usually normal even in the presence of cancer. Therefore, when nodules appear, it is necessary to monitor them and check them regularly. If your doctor suspects that you may have cancer during a physical exam or ultrasound, a biopsy is performed. The results of the biopsy will either rule out the diagnosis of cancer or confirm surgical treatment. Specifically, thyroid cancer can only be diagnosed after surgical removal of the nodule. Thyroid nodules are very common, but less than 1 in 10 will be diagnosed with thyroid cancer. Treatment of thyroid cancer Surgery. The first and main step in the treatment of all types of thyroid cancer is surgery. The extent of surgery for differentiated thyroid cancer may be to remove only the lobe associated with the cancer, called a lobectomy, or to remove the entire thyroid gland, called a thyroidectomy. The extent of surgery will depend on the size of the tumor and whether the tumor has spread outside the thyroid gland. If the tumor involves both lobes of the thyroid gland or the examination shows that it has spread outside the gland, a total thyroidectomy will be recommended. If there is thyroid cancer (lymph node metastases) in the neck lymph nodes, these lymph nodes may be removed during primary thyroid surgery or sometimes as a second procedure. However, if the cancer is small, in only one lobe of the gland, and if it has not spread to the lymph nodes, a lobectomy may be a good option. Recent research even suggests that small tumors less than 1 cm in diameter, called papillary thyroid microcarcinoma, can be safely monitored without surgery. If the thyroid gland has been completely removed, the person will need to take medication (thyroid hormones) for the rest of their life. However, if you have had a lobectomy, you may not need thyroid hormones. Thyroid cancer is often cured with surgery alone, especially if the cancer is small. If the cancer is larger, has spread to the lymph nodes, or if the doctor thinks there is a high risk of the cancer recurring, surgery may be needed to remove the thyroid gland. The first step in the treatment of all types of thyroid cancer is surgery. The extent of surgery for differentiated thyroid cancer can be to remove only the lobe associated with the cancer, called a lobectomy, or to remove the entire thyroid gland, called a total thyroidectomy. The extent of surgery will depend on the size of the tumor and whether the tumor has spread outside the thyroid gland. If your tumor involves both lobes of the thyroid gland or the test shows that it has spread outside the gland, a total thyroidectomy will be recommended. If there is thyroid cancer (lymph node metastases) in the neck lymph nodes, these lymph nodes may be removed during primary thyroid surgery or sometimes as a second procedure. However, if your cancer is small, in only one lobe of the gland, and if it has not spread to the lymph nodes, a lobectomy may be a good option. Recent research even suggests that if you have a small tumor less than 1 cm in diameter, called papillary thyroid microcarcinoma, you can be monitored very safely without surgery. If you have had your entire thyroid gland removed, you will need to take thyroid hormone medication for the rest of your life. However, if you have had a lobectomy, you may not need to take thyroid hormones. Thyroid cancer is often cured with surgery alone, especially if the cancer is small. If your cancer is larger, has spread to the lymph nodes, or your doctor thinks you are at high risk of the cancer recurring, radioactive iodine therapy may be used after your thyroid is removed. Radioactive iodine therapy. Thyroid cells and most differentiated thyroid cancers absorb iodine, so radioactive iodine can be used to remove any remaining normal thyroid tissue and potentially destroy any remaining cancerous thyroid tissue after a thyroidectomy. The procedure for removing remnants of thyroid tissue is called radioactive iodine ablation. Because most other tissues in the body do not absorb or concentrate iodine efficiently, the radioactive iodine used in an ablation procedure usually has little or no effect on the boundaries of the thyroid gland. However, in some patients receiving higher doses of radioactive iodine to treat metastatic thyroid cancer, the radioactive iodine can affect the glands that produce saliva and cause dry mouth. If higher doses of radioactive iodine are needed, there may be a small risk of developing other cancers later. This risk is very small and increases with the dose of radioactive iodine. The potential risk of treatment can be minimized by using the lowest possible dose. Balancing the potential risks and benefits of radioactive iodine therapy is an important discussion you should discuss with your doctor if radioactive iodine treatment is recommended. In general, the prognosis for differentiated thyroid cancer is excellent, especially if the person is younger than 55 and has a mild form. If papillary thyroid cancer has not spread outside the thyroid gland, such patients rarely die from thyroid cancer. If a person is older than 55 or has a larger or more aggressive tumor, the prognosis remains very good, but the risk of cancer recurrence is higher. The prognosis may not be as good if the cancer is more advanced and cannot be completely removed by surgery or destroyed by radioactive iodine treatment. However, even after successful treatment, lifelong monitoring will be required. https://www.thyroid.org/thyroid-cancer/ https://www.cancerresearchuk.org/about-cancer/thyroid-cancer/causes-risks
