Dr. Jeffrey Zigman on Thyroid Nodules
Dallas endocrinologist Dr. Jeffrey Zigman answers questions about thyroid nodules.
Are thyroid nodules the same thing as thyroid cancer?
Not necessarily. Thyroid nodules are lumps that occur within the thyroid gland, which is a butterfly-shaped gland located in the neck slightly above where the collarbones meet.
Only about 5 to – at most – 15 percent of thyroid nodules harbor thyroid cancer; most are benign (noncancerous) and cause no problems if left untreated.
Thyroid nodules that grow too big, however, can crowd vital structures in the neck, which can lead to difficulty swallowing and breathing, as well as poor blood flow to and from the head. Large, visible nodules can cause mental anguish.
In addition, thyroid nodules can overproduce thyroid hormone (hyperthyroidism), which, if severe, can cause symptoms such as palpitations, hand tremors, and anxiety, and can contribute to dangerous heart arrhythmias. Rarely, thyroid nodules can represent other types of cancer that have spread to the thyroid.
How common are thyroid nodules and what are the symptoms?
Thyroid nodules are fairly common. Depending on the population, they occur in between 20 and upwards of 70 percent of people. They’re more common in women and more likely to develop as people get older.
Signs and symptoms of thyroid nodules can include a lump in the neck that can be seen or felt; difficulty swallowing solid food or pills; hoarseness; difficulty breathing; and faintness when raising the arms above the head. Occasionally, they are associated with discomfort.
People who experience these issues – particularly those with a lump that is growing in size – should be evaluated for thyroid nodules by a doctor.
How are thyroid nodules diagnosed?
When a thyroid nodule is suspected, most patients undergo an ultrasound study of the thyroid gland. This test helps us to confirm that the nodule is present, determine if the nodule has any suspicious features, and identify if other nodules are present.
When thyroid nodules are confirmed, we typically test the level of thyroid-stimulating hormone (TSH) in the blood to determine if the nodules are overproducing thyroid hormone (hyperthyroidism). If so, we usually also obtain a test called a thyroid scan and uptake study.
Importantly, if a nodule exhibits certain suspicious features on ultrasound, we may recommend a biopsy, during which thin needles are used to take tissue samples of the nodule. In our practice, we routinely save two samples: one to be examined under a microscope and – if there’s uncertainty about those results – one to be sent for more refined molecular diagnostic evaluation.This sophisticated testing can help us best assess the risk for thyroid cancer and recommend the most appropriate management strategy.
How are thyroid nodules treated?
For most people with thyroid nodules, no specific treatment is needed other than routine evaluations in the correct medical setting.
If testing shows a high risk that a thyroid nodule harbors thyroid cancer, treatment usually involves surgical removal of the thyroid gland (thyroidectomy) by a skilled thyroid surgeon. Thyroidectomy also may be indicated for large nodules that interfere with breathing, swallowing, or blood flow.
Thyroid nodules that are overproducing thyroid hormone can be treated with oral radioactive iodine, oral anti-thyroid medications, or surgery.
Nodules that are rapidly growing due to blood or fluid accumulation can be easily drained (usually with minimal discomfort) at the bedside with fine-needle aspiration.
Although some thyroid nodules – especially smaller ones or those filled with fluid – can go away on their own, they tend to gradually grow, even when they’re benign.