The thyroid is a gland located in the lower part of the neck in the midline. The main function of the thyroid is to produce a hormone that controls your body’s metabolism and energy level. The thyroid hormone plays a big role in many of your body’s essential functions.
Thyroid nodules are common. About 5% of people have a thyroid nodule that can be felt on examination. About 50% have a nodule that can be seen on ultrasound. Most people with one or more thyroid nodules actually have normal thyroid hormone levels. Sometimes you are aware of a nodule by feeling a lump in the lower part of your neck. Sometimes nodules are detected on a physical exam with a physician. And sometimes nodules are seen “incidentally” when you have a scan to evaluate another problem, such as a CT or MRI.
Thyroid nodules are often treated by primary care physicians, internists, endocrinologists, otolaryngologists (ENT), and general surgeons. Whenever considering management and workup of a nodule, risk factors for cancer are considered. This includes a history of radiation, nodule growth, hoarseness, swallowing problems, and a family history of thyroid cancer. Other potential risks include nodules in children younger than 18 and adults over age 70.
For most people, small nodules are low risk and can be safely monitored with ultrasound. For nodules larger than 1.5 cm (a little over half an inch) or with a concerning appearance on ultrasound, a biopsy should be considered. Thyroid fine needle aspiration (FNA) is a minimally invasive method to biopsy a thyroid nodule and is extremely accurate. It is the test of choice to determine the risk of malignancy. The procedure usually takes less than 30 minutes and is relatively painless.
Typically, FNA results fall into one of three broad categories – benign, malignant (cancerous), and indeterminate. Indeterminate nodules have an intermediate risk of cancer and often additional testing or surgery is recommended. Sometimes surgery is needed even for benign nodules. Larger nodules can cause compressive symptoms including tightness in the neck, swallowing difficulty, breathing difficulty, and voice change. For these patients, removing the portion of the thyroid with the nodule often helps alleviate these symptoms. Patients who have benign nodules on FNA should be followed with ultrasound. The biopsy should be repeated if there is significant growth on the ultrasound or if the patient starts to develop symptoms.
Suspicious or indeterminate nodules generally require more testing. For certain nodules, sending the FNA biopsy for genetic testing can help clarify the risk of cancer. Removing the portion of the thyroid with the nodule is sometimes necessary when the diagnosis is still unclear after FNA. In this case, pathologists can examine the nodule in its entirety to give a final diagnosis. This is called a diagnostic thyroid lobectomy. If the result is benign, usually no other treatment is needed. If cancerous, you might require additional surgery to remove the rest of the thyroid.
The majority of patients who have surgery to remove the half of their thyroid that has a nodule will maintain adequate thyroid function and will not need thyroid hormone replacement. For those who experience a drop in their thyroid function after surgery, a daily medication to replace their thyroid hormone is necessary.
If you are diagnosed with a small and less aggressive thyroid cancer, removing the half of the thyroid with the cancer may be the only treatment needed. You should continue to see your physician regularly for monitoring. For larger or more aggressive cancers, removing the entire thyroid is often necessary.
Thyroidectomy is generally a safe and well-tolerated operation. Most patients who have half of the thyroid removed (thyroid lobectomy or hemithyroidectomy) can return home the same day. Patients who have their entire thyroid removed (total thyroidectomy) may remain overnight in the hospital to have their calcium monitored. The risks of thyroid surgery include bleeding, infection, unfavorable scar, hoarseness, and low calcium level. The risk of permanent hoarseness or low calcium level is less than 1%.
In summary, thyroid nodules are common and the vast majority of thyroid nodules are benign and do not impact the health or quality of life of the patient. Even so, thyroid nodules need to be appropriately evaluated. This may include ultrasound, FNA, or surgery. Thyroid surgery is safe with a relatively short recovery period. Even when nodules are cancerous, the prognosis after appropriate treatment is usually excellent. If you have questions about your thyroid, contact a SacENT physician at (916) 736-3399.