Benign and Malignant Thyroid Diseases
The thyroid gland is a small, butterfly shaped gland in the throat below the Adam’s apple that produces hormones which regulate many important bodily functions, including: metabolism, brain development, heart function, digestion and muscular functionality. A variety of different types of growths can occur on the thyroid, most of which are benign. However, some can be malignant and spread to other parts of the body.
Benign thyroid conditions include an enlargement or goiter and thyroid nodules. Though the thyroid can generally not be felt, when it is enlarged a patient or their doctor may become aware of the gland’s abnormally large size, which is known as a goiter. Goiters can be diffuse—this is when the entire gland is large—or nodular—when nodules or bumps on the gland can be felt. Usually this condition is caused by a hormone imbalance, such as having a diet lacking in iodine. This can affect hormone levels and result in a goiter. Thyroid nodules or bumps on the gland are most often benign and tend to occur most in older adults. However, 2 to 3 in 20 are cancerous. Many thyroid nodules are too small to feel and can only be found through an ultrasound. Most nodules are fluid filled cysts, while some are solid. Even most of the solid ones are not cancerous. Benign nodules can be left untreated but should be watched closely by a physician to ensure they are not growing or causing any issues.
When it comes to thyroid cancers, there are three main types—Differentiated, Medullary & Anaplastic. Each type has a different prognosis.
Differentiated thyroid cancers make up the bulk of cases, and there are three main types:
Papillary Cancer: These are the most common amongst thyroid cancers, making up about 80% of cases. Generally, these are slow growing cancers that occur in only one lobe of the gland. They do have the potential to spread, and often affect the neck’s lymph nodes. Follicular cancers occur in about 10% of cases and are often caused by a lack of iodine in the diet. They rarely spread to lymph nodes but can spread to other body parts, like the lungs and bones. In most cases, the prognosis is still good for follicular cancer, though not as good as it is for papillary cancer. The final type of differentiated thyroid cancer is Hurthle cell cancer, a type of thyroid cancer that is less common and harder to find and treat.
The second most common type of thyroid cancers are Medullary thyroid carcinoma, accounting for 4% of thyroid cancers. These cancers are more difficult to find and treat and can spread to lymph nodes, lungs and liver before being found. There are two types of Medullary thyroid cancers, Sporadic MTC, which occurs mostly in older adults and often in one lobe, and Familial MTC, which is inherited and often occurs during childhood and may be linked with other types of tumors.
Anaplastic thyroid cancer is the least common form of the disease, with cells hardly resembling thyroid cells. It is possible that this form of the disease develops from existing papillary or follicular cancer and can spread quickly and be difficult to treat.
- A lump or swelling in the neck
- Pain in the front of neck and up to ears
- Trouble swallowing and/or breathing
- Hoarse voice or other vocal changes
- Constant cough not caused by a cold
Changes in the thyroid are often discovered through a physical exam, but can also be found when a blood test indicates the thyroid isn’t functioning properly. If benign thyroid disease is discovered, oftentimes the recommendation may be watchful waiting. That means that at specified intervals, a patient will have a physical exam, blood test and possibly an ultrasound to ensure the nodules remain unchanged. If the bloodwork indicates that the patient requires more thyroid hormone, they may begin hormone therapy. Surgery for noncancerous nodules is only indicated when their size impedes breathing or swallowing.
When thyroid cancer is found, surgery is usually required, although sometimes very small cancers with a low risk of growing may be carefully monitored by your doctor through regular ultrasound and bloodwork. However, the most common treatment for thyroid cancer is surgery. Whether the surgeon removes the whole thyroid (thyroidectomy) or a portion of it (lobectomy) depends on the size and type of the thyroid cancer and whether it has spread beyond the thyroid. The surgeon may also remove nearby lymph nodes. One risk of this surgery is damage to the parathyroid gland which can result in low calcium levels in your body. Another risk is that surgery may affect your vocal cords, resulting in voice changes or vocal cord paralysis. After surgery, radioactive iodine treatment in a capsule or liquid form is often used to destroy any remaining thyroid tissue. After a specified period following radioactive iodine treatment, patients generally are prescribed thyroid hormone medication which they take for the rest of their lives. Some advanced cases of thyroid cancer may require other treatments, including external radiation therapy, chemotherapy, targeted drug therapy and palliative care.Previous Page Last Review Date: October 21, 2020