Diagnosing and Treating Benign & Cancerous Thyroid Nodules
The thyroid is a butterfly-shaped gland located at the front of the neck. It secretes calcitonin and thyroxine, hormones that regulate several important body functions, including heart rate, blood pressure, body temperature and weight.
Thyroid nodules are collections of cells that grow in and from the thyroid. Nodules can either be benign (non-cancerous) or malignant (cancerous). Some patients with nodules also have over- or under function of the thyroid gland, a condition also known as hyper- or hypothyroidism.
- Benign nodules are the most common type. More than 70 percent of all thyroid nodules don’t grow or spread, and often don’t need to be removed unless the patient is symptomatic or has overactivity of the gland.
- Malignant nodules, or thyroid cancer, can grow and spread to other organs if not treated.
Some people are at a higher risk for developing thyroid nodules or thyroid cancer because of certain factors:
- Women are three times as likely as men to develop thyroid cancer.
- It can occur at any age, but patients are generally between 20 to 60 years old.
- People with diets that are low in iodine, especially when coupled with exposure to radiation during childhood are at higher risk.
- Those with a family history of thyroid cancer are at higher risk for developing thyroid cancer themselves.
Types of Benign Thyroid Disorders
- Multinodular goiter: A goiter is enlargement of the thyroid gland, which can be caused by iodine deficiency or a thyroid disorder. A multinodular goiter contains multiple distinct nodules.
- Hyperthyroidism: This is the overproduction of thyroid hormones, which can occur when a nodule or goiter produces the hormones. It can also be the result of Graves' disease, an immune system disorder that results in the overproduction of thyroid hormones, or toxic multinodular goiter.
Types of Thyroid Cancer
- Papillary carcinoma and follicular carcinoma: These are the most common types of thyroid cancers, accounting for between 80 to 90 percent of cases. They originate in the thyroid hormone producing cells.
- Medullary thyroid carcinoma (MTC): This is a uncommon type of thyroid cancer, often associated with familial genetic mutations such as Multiple Endocrine Neoplasia, that accounts for just five to 10 percent of cases. It originates from the parafollicular cells (also called C cells) of the thyroid, which produce the hormone calcitonin. Again, although it can be sporadic, this is often a genetic form of thyroid cancer that can run in families.
- Anaplastic thyroid carcinoma: This is a very rare form of thyroid cancer that is more likely to spread beyond the gland. This is often confused with poorly differentiated thyroid cancer but is not as treatable.
How are Thyroid Nodules Diagnosed?
Physicians will test for the presence of thyroid nodules in several ways:
- Physical exam: This is a simple exam in which the physician feels the patient’s neck in search of nodules or enlarged lymph nodes.
- Blood Tests: Blood is drawn to detect abnormal levels of thyroid stimulating hormone (TSH).
- Thyroid scan: To perform a scan, physicians give patients an oral substance containing radioactive iodine. Nodules that absorb more of the radioactive substance than the surrounding thyroid tissue are considered less likely cancerous. Nodules that don’t absorb as much substance are more likely to be cancerous. We reserve use of this scan for patients who have under- or overactivity of the thyroid gland, and do not routinely use this scan for patients whose thyroid function is normal.
- Thyroid ultrasound: An ultrasound helps determine the size, shape, contour and consistency of a nodule. It also produces images to determine whether these growths are likely to be liquid-filled cysts or solid tumors and determine need for biopsy.
- Biopsy: Doctors examine tissue samples for evidence of cancer.
- A fine needle aspiration is performed by taking a small sample of the cells using a small needle. This procedure is performed through the skin and can be done with just a small local injection of anesthesia, allowing the patient to go back to work or home just after the procedure is done.
- In a surgical biopsy, a small incision is made and a small section of the nodule is removed to determine if it is cancerous. This procedure is far less common than FNA.
How are Thyroid Nodules Treated?
Benign nodules: Occasionally, a nodule that is benign may require surgery. This is especially true if it has grown so large that it makes it hard to breathe or swallow, if the nodule is growing in size or if the patient has overactivity of the gland (hyperthyroidism).
Surgery is also considered for people with large multinodular goiters when they constrict airways, the esophagus or blood vessels. Nodules that surgeons consider “indeterminate” or
“suspicious” also need surgical removal so they can be examined for signs of cancer.
Non-surgical treatment options may be used for benign thyroid nodules that cause uncomfortable symptoms:
- Radioactive iodine treatment
- Anti-thyroid hormone medication
Cancerous nodules: The usual treatment for malignant nodules is surgical removal of the thyroid gland, a procedure called a total or near-total thyroidectomy. When cancer has spread beyond the gland to other tissue surgeons may perform a neck dissection to remove the thyroid and surrounding tissue which contains lymph nodes. Thyroid surgery is followed by thyroid hormone replacement for the rest of the patient’s life.
MedStar Washington Hospital Center endocrine surgeons perform more thyroid operations than any other medical center in the region. Today nearly all thyroid operations at the hospital are performed using minimally invasive techniques.
During a minimally invasive thyroidectomy, our surgeons often make a one inch or less incision (instead of a large five inch or larger incision). During the minimally invasive procedure, weuse a small set of instruments that allow us to operate through this small incision with the same precision and ease with which we perform the more traditional open operation. Then we precisely remove all or most of the gland. Patients experience a faster recovery—and a better cosmetic result with just a small scar.