What's Special About U-M's Treatment of Thyroid Nodules?
University of Michigan endocrine surgeons perform their own thyroid ultrasounds. Their overall experience and insight into the disease process allows them to gather necessary information at the time of the office visit to formulate a specific plan. Some patients will require biopsies of their nodules using a very small needle and local anesthetic. Many times the biopsy can be performed at the time of the office visit by their surgeon, streamlining patient care and avoiding unnecessary waiting for other appointments.
For patients with nodules that need to be removed, many of these surgeries can be performed as a minimally invasive procedure. It is common for patients undergoing removal of half of their thyroid gland to be discharged home only several hours after their surgery is completed.
What Are Thyroid Nodules?
A thyroid nodule is a collection of cells within the thyroid gland that is surrounded by a distinct capsule of tissue. For various reasons, these cells grow at a rate different from the surrounding thyroid tissue. Thyroid nodules are fairly common and are often found on physical exam in about 5-8% of patients and in up to 60% of patients undergoing imaging studies. Nodules are more common in women and increase in incidence with age. Nodules within the thyroid can be single or multiple. They can exist within a normal sized thyroid gland, or they may cause an enlargement of the thyroid gland, which is called a multinodular goiter. 95% of thyroid nodules are benign, however any time a nodule is discovered the possibility of cancer must be excluded.
Other names for Thyroid Nodules:
- Thyroid adenoma
- Colloid nodule
- nodular hyperplasia
What Are the Symptoms of Thyroid Nodules?
Many patients with thyroid nodules have no symptoms related to the nodule. Some patients, however, may notice a gradually enlarging lump in the front of their neck, and/or a feeling of pressure or discomfort, difficulty swallowing food, discomfort radiating up to the ear, and sometimes difficulty breathing. If the nodule produces too much thyroid hormone, patients may experience symptoms of hyperthyroidism, such as sweating, rapid heart rate, unintended weight loss, change in their hair or skin, anxiety, changes in their bowel habits, and other manifestations.
What Causes Thyroid Nodules?
Nodules are caused by thyroid tissue, which can be benign or cancerous, growing more quickly than surrounding thyroid tissue. Nodules may be solid, fluid-filled, or a mix of both. In most cases of benign nodules, no one is entirely sure of the cause. Some thyroid disorders can be the result of genetic influences or autoimmune disorders.
How Are Thyroid Nodules Diagnosed?
In some cases, the patient, a friend or family member may notice there is a lump near the bottom of the neck. In other cases, a healthcare provider may feel a nodule during a physical examination. In still other instances, thyroid nodules are found incidentally while performing an imaging study (CT scan, MRI, ultrasound) to evaluate another medical condition.
How Are Thyroid Nodules Evaluated?
In order to further evaluate a thyroid nodule, several tests are routinely performed.
Thyroid ultrasonography, or ultrasound, is a way of evaluating the thyroid gland by using high-frequency sound waves that pass through the tissues of the body to generate images of the thyroid gland and nearby structures. All nodules should be evaluated with a dedicated thyroid ultrasound.
Ultrasound is the most sensitive and specific radiologic test to examine the appearance of a thyroid nodule. The latest ultrasound techniques can help physicians identify nodules and aid in determining which nodules might be cancerous. Your surgeon may perform this scan while you are in the clinic.
Thyroid ultrasonography is also used for guidance during fine needle biopsy, ensuring that tissue is obtained from the nodule in question. Thyroid ultrasound provides a precise method for detecting a change in the size of the nodule and is important for long term follow-up of the nodule. A benign appearing nodule that is stable in size, or shrinking, is unlikely to be malignant or require surgical treatment. Your physician will determine how often an ultrasound needs to be performed.
Fine Needle Aspiration Biopsy
Sometimes it is necessary to obtain a tissue sample from the nodule. This procedure is called a fine needle aspiration and is a form of biopsy. A fine needle aspiration is a simple test that can be done in your doctor's office. After numbing the skin with local anesthetic a very small needle is inserted through the skin into the nodule, and a small amount of tissue from the nodule is removed and given to a pathologist to examine under a microscope. Results are usually available within several days.
As good as thyroid needle biopsy is, about 30% of biopsy specimens are found to be indeterminate or non-diagnostic and the pathologist cannot be certain whether the nodule is cancerous or benign. This is particularly common with cystic or fluid-filled nodules, which have very few thyroid cells in them. In these cases, a physician experienced in thyroid disease can use other information to decide whether or not an operation is needed for a definitive diagnosis.
The great majority of patients found to have a thyroid nodule do not need surgery and simply need to be followed with physical examination, lab work and ultrasound examinations.
Thyroid Uptake Scan
A Thyroid uptake scan is a test once commonly used to help evaluate thyroid nodules. It is rarely performed today, due to improvements in ultrasound and fine needle aspiration. It is most commonly used for patients who are found to be hyperthyroid. A thyroid uptake scan is a picture of the thyroid gland taken after a small dose of a radioactive material has been administered. It helps show areas of the thyroid gland that are functional and non-functional. A nodule that is functioning excessively is called a "hot" nodule, while an under-performing nodule is called a "cold" nodule.
It is important to remember that neither a thyroid scan nor radioactive iodine treatment should ever be given to a pregnant woman, because small amounts of the radioactive material will end up in the patient's breast milk and can be transmitted to the fetus. This can damage the baby's developing thyroid gland. Babies whose mothers have recently received radioactive iodine should not be breast fed either. Attempts at pregnancy should be delayed for at least a year.
How Are Thyroid Nodules Treated?
Your medical team will use the tests we just mentioned to come up with a plan to best treat your nodule. Most patients who appear to have benign nodules need no specific treatment, and can simply be followed to make sure the nodules don't become a problem over time.
If your physician is concerned that your nodule is malignant/cancerous, surgery will be recommended. Some nodules remain in the indeterminate category, even after fine needle aspiration and other tests are performed. Your physician will discuss options with you regarding this category of nodules. A thyroid with a single nodule that is hyperfunctioning, or "hot", may be treated with surgery, but is usually treated with radioactive iodine. Any nodule or nodules causing compressive symptoms are usually removed surgically.
Surgical options range from removing only the side of the thyroid gland that contains the nodule in question, to removing the entire thyroid gland. Your surgeon will discuss the appropriate surgical options with you.
If surgery is not recommended, it is important to have regular follow-up exams of your thyroid by a physician experienced in such an evaluation.
How is Thyroid Surgery Usually Performed?
Thyroid operations are done in a hospital operating room under a general anesthetic.
An incision is made in the front of the neck along the collar line. The underlying muscles are opened to expose the thyroid gland. The surgeon then removes part or all of the thyroid gland while taking great care not to injure nearby blood vessels or nerves. Every attempt is made to preserve the parathyroid glands. Parathyroids are small glands which manufacture a hormone which controls blood calcium levels. Occasionally, a parathyroid gland may be concealed in or around part of the thyroid that is removed. The thyroid gland and parathyroid glands share some degree of blood supply. If this blood supply to a parathyroid gland is not adequate after the thyroid is removed, the parathyroid gland may be grafted into a nearby muscle within the same incision with the intention that it may recruit new blood supply from that muscle and function again in the near future. The muscles are then repaired and the skin incision is closed with sutures that will either absorb or be removed soon after your operation. Often the skin surface is sealed closed with surgical glue.