Thyroid nodules are an abnormal growth of thyroid cells that forms a lump within the thyroid gland. They are common and often discovered during routine physical examinations. While the majority of nodules are benign (noncancerous), approximately 5 to 10 percent are malignant.
DIAGNOSIS: Most thyroid nodules don't cause symptoms, and thyroid tests are most typically normal even when cancerous nodules are present. Some nodules can be found incidentally through imaging tests such as CT scans or ultrasounds for completely unrelated reasons. Other times, patients may find a thyroid nodule by noticing a lump in their neck while looking in a mirror, buttoning their collar or fastening a necklace.
While thyroid nodules are extremely common, the causes of nodules aren't as clear. It is known that Hashimoto's thyroiditis as well as iodine deficiency is associated with an increased risk of thyroid nodules. Family history seems to play a role as well.
EVALUATION: Once a nodule is discovered, it needs to be evaluated. The doctor will physically exam your thyroid and order blood tests to verify the function of the gland. Determining whether the nodule is cancerous requires specialized tests such as ultrasonography and fine needle biopsy.
A thyroid ultrasound is a key tool in the evaluation. It is very accurate and can determine whether a nodule is solid of filled with fluid. The ultrasound can help identify suspicious nodules as well as find small nodules that are too small to feel during the physical exam. These ultrasounds are also used to guide a needle if the doctor performs a fine needle aspiration biopsy.
If your doctor does identify a thyroid nodule that seems suspicious, a fine needle aspiration biopsy is needed to determine whether cancer is present. During the procedure, your doctor inserts a thin needle in the nodule and removes a sample of cells. The procedure, usually carried out in the doctor's office, takes about 20 minutes and has few risks. Samples are sent to a laboratory and analyzed under a microscope.
TREATMENT: All thyroid nodules that are cancerous, or highly suspicious, should be surgically removed by an experienced thyroid surgeon. If a thyroid nodule isn't cancerous, there are several treatment options.
The first is watchful waiting, which is when a biopsy shows a benign thyroid nodule, the doctor may suggest simply watching, which usually means regular physical exam and thyroid function tests. There will be another biopsy if the nodule grows larger. If a benign thyroid nodule remains unchanged, careful monitoring may be the treatment.
Another is treatment is thyroid hormone suppression therapy. This involves treating a benign nodule with a synthetic form of thyroxine taken in pill form.
Lastly, there is surgery. A nodule clearly benign may require surgery, especially if it's large enough to make it hard to breathe or swallow. Surgery is also the best option for people with goiters, particularly when the goiter constricts airways, the esophagus or blood vessels.
Dr. Scheuller is an Ear, Nose and Throat (Otolaryngologist) specialist and is a member of the American Academy of Otolaryngology Head and Neck Surgery. He practices in Ogden.