Thyroid nodules are solid or fluid-filled lumps that form within your thyroid, a small gland located at the base of your neck, just above your breastbone.
The great majority of thyroid nodules aren’t serious and don’t cause symptoms. Thyroid cancer accounts for only a small percentage of thyroid nodules.
You often won’t know you have a thyroid nodule until your doctor discovers it during a routine medical exam. Some thyroid nodules, however, may become large enough to be visible or make it difficult to swallow or breathe.
Treatment options depend on the type of thyroid nodule you have.
Most thyroid nodules don’t cause signs or symptoms.
Occasionally, however, some nodules become so large that they can be felt or seen and even press on your windpipe or esophagus, causing shortness of breath or difficulty swallowing
In some cases, thyroid nodules produce additional thyroxine, a hormone secreted by your thyroid gland that may result in an unexplained weight loss; intolerance to heat; tremor; nervousness, or rapid or irregular heartbeat.
A few thyroid nodules are cancerous but it’s difficult to tell which nodules are malignant by symptoms alone. Although size isn’t a predictor of whether a nodule is malignant, cancerous thyroid tumors are more likely to be large fixed masses that grow quickly.
Several conditions can cause nodules to develop in your thyroid gland. Lack of iodine in the diet can sometimes cause the thyroid gland to develop nodules. But iodine deficiency is uncommon in the U.S., where iodine is routinely added to table salt and other foods.
Why a person may have an overgrowth of normal thyroid tissue isn’t clear, but such a growth — which is sometimes referred to as a thyroid adenoma — is noncancerous and isn’t considered serious unless it causes bothersome symptoms from its size.
Some thyroid adenomas (autonomous or hyperfunctioning thyroid nodules) produce thyroid hormones outside of the pituitary gland’s normal regulatory influence, leading to an overproduction of thyroid hormones (hyperthyroidism).
Fluid-filled cysts in the thyroid most commonly result from degenerating thyroid adenomas. Often, solid components are mixed with fluid in thyroid cysts. Cysts are usually benign, but they occasionally contain malignant solid components.
Hashimoto’s disease, a thyroid disorder, can cause thyroid inflammation resulting in nodular enlargement. This often is associated with reduced thyroid gland activity (hypothyroidism).
“Goiter” is a term used to describe any enlargement of the thyroid gland. It can be caused by iodine deficiency or a thyroid disorder. A multinodular goiter contains multiple distinct nodules within the goiter, but its cause is less clear.
Although the chances that a nodule is malignant are small:
- You’re at higher risk if you have a family history of thyroid or other endocrine cancers
- Are younger than 30
- Older than 60
- Are a man
- Or have a history of radiation exposure, particularly to the head and neck
A nodule that is large and hard or causes pain or discomfort is more worrisome in terms of malignancy.
Complications associated with thyroid nodules include problems swallowing or breathing. Large nodules or a multinodular goiter — an enlargement of the thyroid gland containing several distinct nodules — can interfere with swallowing or breathing.
Problems can occur when a nodule or goiter produces thyroid hormone, leading to hyperthyroidism. Hyperthyroidism can result in weight loss, muscle weakness, heat intolerance, and anxiousness or irritability.
If a thyroid nodule is cancerous, surgery is usually required. Generally, most or all of the thyroid gland is removed. Most thyroid cancers are found early, though, and have a good prognosis.
In assessing a lump or nodule in your neck, one of the doctor’s main goals is to rule out the possibility of cancer. The doctor will also want to determine if a person’s thyroid is functioning properly.
There are also tests that measure blood levels of thyroxine and triiodothyronine, hormones produced by the thyroid gland, and thyroid-stimulating hormone (TSH), which is released by your pituitary gland, can indicate whether your thyroid is producing too much thyroxine (hyperthyroidism) or too little (hypothyroidism).
The doctor may order an ultrasound of the thyroid which uses high-frequency sound waves rather than radiation to produce images. Nodules are often biopsied to make sure no cancer is present.
In some cases, the doctor may recommend a thyroid scan to help evaluate thyroid nodules.
Nodules that produce excess thyroid hormone — called hot nodules — show up on the scan because they take up more of the isotope than normal thyroid tissue does. Cold nodules are nonfunctioning and appear as defects or holes in the scan.
The length of a thyroid scan varies, depending on how long it takes the isotope to reach your thyroid gland. You may have some neck discomfort because your neck is stretched back during the scan, and you’ll be exposed to a small amount of radiation.
Treatment depends on the type of thyroid nodule. and if a thyroid nodule isn’t cancerous, there are several treatment options.
- If a biopsy shows that a patient has a benign thyroid nodule, the doctor may suggest simply watching your condition, which usually means having a physical exam and thyroid function tests at regular intervals.
- Thyroid hormone suppression therapy involves treating a benign nodule with a synthetic form of thyroxine taken in pill form. The idea is that supplying additional thyroid hormone will signal the pituitary to produce less TSH, the hormone that stimulates the growth of thyroid tissue.
- Occasionally, a nodule that’s clearly benign may require surgery, especially if it’s so large that it makes it hard to breathe or swallow. Surgery is also considered for people with large multinodular goiters, particularly when the goiters constrict airways, the esophagus or blood vessels.
- If a thyroid nodule is producing thyroid hormones, overloading the thyroid gland’s normal hormone production levels, the doctor may recommend the treatment for hyperthyroidism which can include radioactive iodine; anti-thyroid medications, and surgery.
- Treatment for a cancerous nodule usually involves surgery.
**This article originally featured at TheSpectrum.com**