A thyroid nodule is a growth within the thyroid gland. Thyroid nodules are extremely common and can be seen in 5 to 10 percent of women and 1 to 5 percent of men. Studies have shown that the chance of having a thyroid nodule increases with increasing age and that up to 60 percent of women over the age of 60 years may have a thyroid nodule.
A patient may find a nodule on their own by feeling their neck (palpation), a physician may note it on physical exam, or it can be incidentally found by an imaging study (ultrasound, CT scan, etc.).
If blood tests show abnormal thyroid function, an ultrasound of the neck is usually performed, and thyroid nodules can be found in this way. Generally, only nodules 1 cm or greater are evaluated by FNA biopsy, since they have a greater potential to be cancer. Occasionally, there may be nodules less than a centimeter in size that require evaluation, because of certain risk factors.
A risk factor is anything that increases a person's chance of getting a disease. Different diseases have different risk factors. Some risk factors can be controlled with lifestyle changes. Other risk factors cannot be changed. When a patient is diagnosed with a thyroid nodule, it is most important to rule out thyroid cancer. Thyroid cancer is not common, but may occur in 5 to 10 percent of patients with thyroid nodules. There are several factors that may increase the risk for having cancer. These risk factors include:
- family history of thyroid cancer or thyroid cancer syndromes
- personal history of radiation to the head, neck, or upper chest
- age < 20 years or > 70 years
- male gender
- nodules that are increasing in size nodules that have a hard consistency
- enlarged neck lymph nodes
- symptoms of hoarseness
Having one or more of the above risk factors does not mean that you will develop a thyroid cancer. Understanding your risk factors will help you determine, what, if any, precautions and possible screening options you should consider.
Thyroid nodules are often asymptomatic (i.e. do not cause symptoms), and patients may not even know they have them. In particular, small nodules often do not produce symptoms. However, patients with larger nodules may notice a fullness in the neck below the Adam's apple, may experience difficulty swallowing solid foods, or have a sense of pressure. Compressive symptoms, rapid growth of the nodule, or enlarged lymph nodes should prompt evaluation by your physician.
If you have one or more of the above symptoms, it does not mean that you have a thyroid nodule. If you think you have a nodule, please call your doctor.
The treatment for a thyroid nodule will depend on whether it is benign, malignant [cancer], or indeterminate.
A benign pathology result means that there is no evidence of cancer. Most patients with a benign result will not need surgery, unless the nodule is large and causing compressive problems in the neck or if it is bothersome. The type of surgery will depend on the location of the nodule and whether there are multiple or bilateral nodules in the thyroid, If only one side of the thyroid is affected, a thyroid lobectomy is used to remove the affected side of the thyroid. If multiple, bilateral nodules are present, a total thyroidectomy is used.
Typically, when the biopsy demonstrates a cancer, it is either a papillary thyroid cancer (most common) or a medullary thyroid cancer. Most thyroid cancers will be treated with a total thyroidectomy and possible removal of some of the lymph nodes in the neck. The addition of additional postoperative therapy will ultimately depend on the type of cancer, how big the cancer is, and if there is any spread outside the thyroid.
There are a number of different types of tumors that are considered indeterminate on FNA: follicular neoplasm, Hurthle cell neoplasm, and atypical lesion. An indeterminate lesion means that the FNA cells do not look completely normal, but that in order to make a diagnosis of cancer the whole nodule has to be examined under the microscope to see if there is invasion or growth outside of the nodule. This can only be done by removing part or all of the thyroid through a thyroid lobectomy (most commonly), or, if needed, a total thyroidectomy.