What are thyroid nodules?

Thyroid nodules are growths that occur in the thyroid gland forming a lump or bump within the otherwise smooth thyroid surface. Thyroid nodules are common, occurring in 40% of women and 30% of men during their lifetime. Most thyroid nodules are benign, but some are cancerous. When people hear they have a thyroid nodule they worry about cancer and the need for surgery. Thyroid cancer only accounts for approximately 5-15% of all thyroid nodules, but people understandably get concerned about the need for biopsy and ultrasound scans. Here are the top five worries people have when they hear they have a thyroid nodule:

Top 5 Worries About Thyroid Nodules

1. What causes thyroid nodules?

One of the first worries people have when they hear they have a thyroid nodule is what caused it. The cause of most thyroid nodules is not known. In virtually 100% of cases it is not due to something you did or something you ate. Several conditions, however, have been linked to the development of thyroid nodules including iodine deficiency and overgrowth of normal thyroid tissue. Diets deficient in iodine can predispose individuals for the development of thyroid nodules. Portions of the world continue to lack iodine in their diets, however in the United States and most other countries, the presence of iodine in our daily diets makes this an unlikely cause for thyroid nodules. If you have the internet, you do not have an iodine deficiency. 

Thyroid nodules are most commonly caused by an overgrowth of normal thyroid tissue for reasons that are not well understood. These thyroid nodules are commonly called follicular adenomas or thyroid adenomas. (the follicular cell is a normal appearing thyroid cell) Thyroid nodules deemed to be follicular adenomas are clearly not cancerous, are not worrisome, and do not require removal except if they are symptomatic. Rarely, a thyroid nodule will overproduce thyroid hormone and be the cause of hyperthyroidism. For some reason these excessive thyroid hormone producing nodules lose their ability to be regulated by the pituitary gland’s production of Thyroid Stimulating Hormone (TSH).

2. Do I need a biopsy of my thyroid nodule?

When people hear they have a thyroid nodule, they immediately think of the dangers and worry about needing a biopsy of their nodule. Thyroid nodules are often found when a doctor examines a patient's neck and feels thyroid gland. Thyroid nodules are also frequently discovered when a patient gets an x-ray, CT scan, MRI, or ultrasound the neck or chest for some other reason. While most thyroid nodules are benign (85-95%), often times a fine- needle aspiration (FNA) biopsy is needed to obtain more information about how a thyroid nodule is behaving. We just call this a “needle biopsy”. A needle biopsy is typically done for larger nodules (>1cm or 3/8 inch), symptomatic nodules, nodules that have suspicious features on ultrasound, nodules that are changing in appearance, and/or thyroid nodules that have increased in size. The results of a thyroid needle biopsy are categorized according to the Bethesda System for Reporting Thyroid Cytopathology for Thyroid Nodules. The diagnostic categories are as follows:

1. Nondiagnostic or unsatisfactory
2. Benign
3.  Atypia of undetermined significance (AUS) or follicular lesion of    undetermined significance (FLUS)
4.  Follicular neoplasm or suspicious for a follicular neoplasm
5.  Suspicious for malignancy
6.  Malignant

Second or third thyroid biopsies do not erase or eliminate the results of previous biopsies of the same thyroid nodule. When a biopsy returns atypical or suspicious cells, additional molecular/genetic testing can be undertaken to gain more information regarding whether the thyroid nodule is cancerous or not. No further testing on benign, very suspicious, or cancerous thyroid nodules is necessary. Biopsies are not perfect, however, and expert ultrasound can diagnose whether a thyroid nodule is benign, atypical/suspicious, or cancerous in most cases. Patients should also realize that thyroid biopsies are only as good and reliable as the people performing them and the pathologists who are evaluating the cells. Therefore, biopsies of thyroid nodules should be performed and evaluated by high-volume centers and clinicians when possible.

3. Is my nodule thyroid cancer?

The number one question patients have when they are diagnosed with a thyroid nodule is if the nodule is cancer. An excellent ultrasound is the cornerstone of determining whether a thyroid nodule is malignant (cancerous) or benign (non-cancerous). In very rare circumstances, blood tests can provide additional information regarding a thyroid cancer. The likelihood that a thyroid nodule is cancerous is quite low (5%-15% of all thyroid nodules). Risk of cancer in a thyroid nodule increases with the following factors:

• Age less than 30 years of age
• Age greater than 50 years of age
• Male gender
• A positive family history of thyroid cancer
• A positive family history of other endocrine cancers
• A history of significant radiation exposure
• Larger thyroid nodules
• Vocal cord paralysis (hoarseness)

Thyroid cancers located within thyroid nodules are challenging to diagnose since they rarely cause symptoms. Additionally, almost all thyroid cancers cannot be detected with a blood test or routine labs. Unfortunately, thyroid cancer can be present for years without any symptoms or without the patient even knowing. In fact, 50% of thyroid nodules that are cancerous are not even diagnosed until after surgical removal. Expert evaluation of thyroid nodules is paramount to obtaining the correct treatment plan. Surgery is the mainstay for treatment of thyroid cancer.

4. Do I need surgery for my thyroid nodule?

 When people hear they have a thyroid nodule, they worry about surgery and if surgery will be required to remove their thyroid nodule. We have written a very informative section on Thyroid Cancer Surgery at our website. Almost all thyroid nodules which are malignant or highly suspicious of malignancy are treated with surgery. Surgery is very frequently needed for nodules that have atypical or suspicious cells on biopsy. Surgery is the mainstay of curing thyroid cancer.

The best chance to cure thyroid cancer is with the first (and only) operation. Thyroid cancers that are improperly evaluated and treated incompletely will recur at a 20%-30% rate. Only expert thyroid cancer surgeons should be performing thyroid surgery because the risk to the patients, including the nerves to the voice box and glands that control calcium, are significantly higher in the hands of surgeons that do not perform these types of surgery frequently.

Thyroid nodules that are benign on biopsy may be observed. This is provided that the nodule is not overactive/toxic (causing hyperthyroidism), large (4 cm or greater; or >1.5 inches) or progressing in size, symptomatic, part of a goiter that is extending into the chest cavity, or pushing the windpipe (tracheal) or swallowing tube (esophagus). The duration of observation is somewhat arbitrary. Observation usually implies repeating thyroid blood tests, ultrasound, and physical examination in approximately 12-18 months (an ultrasound every 3 or 6 months is not indicated for benign nodules). If the thyroid nodule should increase in size or establish symptoms, repeat biopsy or surgery may be indicated. Of note, large nodules can harbor cancer (10.4%- 22% of the time) that is not diagnosed with FNA biopsy preoperatively. Thyroid nodules that don’t change over a period of years, however, may never require any treatment whatsoever

To have a world-class evaluation of your thyroid nodule, become our patient here.

5. What surgery is best for my thyroid nodule?

When people realize they have a thyroid nodule, they worry about surgery, but they also worry about what kind of surgery. Many people are concerned that they will have their entire thyroid removed. They have friends who have had their thyroid removed and are nervous about their thyroid hormone levels afterwards.

Since surgery is the critical component of the treatment and cure of thyroid nodules, we need to know how much thyroid to remove—some of it or all of it. Too much thyroid surgery, where too much of the gland is removed, can be detrimental, while not removing enough of the thyroid gland can leave behind disease that will require additional surgery in the future. The goal of thyroid surgery is to cure the patient while preserving a normal half of the thyroid gland (for natural thyroid hormone production), when possible, along with the important structures in the neck. Less surgery means less risk.

Many thyroid cancers within thyroid nodules can be treated appropriately with the expectation of cure by removing only half of the thyroid along with the lymph nodes behind the thyroid that are at risk. Thyroid cancer that has spread to lymph nodes or surrounding structures in the neck (muscle, nerve, windpipe, etc.) requires complete removal of the thyroid along with affected compartments of lymph nodes and surrounding structures that are involved (neck dissection).

Expert evaluation of thyroid nodules is very important.

Expert evaluation and surgical planning for thyroid nodules is a must. The wrong surgery or one performed with unskilled and inexperienced hands can have devastating complications and lead to additional surgeries down the line. The correct surgery for a thyroid nodule performed adeptly the first time essentially eliminates complications and the need for further surgery. The extent of the operation, including total removal of the thyroid gland (total thyroidectomy) versus removal of half of the thyroid gland (thyroid lobectomy), are discussed in more detail here.

Summary About Thyroid Nodules

To wrap up, thyroid nodules are very common, more so in women than men. While most thyroid nodules are benign, surgery is necessary in many cases, particularly for thyroid cancers. Finding an expert team to work-up, diagnose, and treat your thyroid nodule is essential. Inexperience in evaluation, biopsy, and surgery for thyroid nodules will lead to poor outcomes and complications. Entrust only the best when it comes to care and treatment of your thyroid nodules!

Additional Resources

• Become our patient here.
• Learn more about the the Clayman Thyroid Center.
• Learn more about the Hospital for Endocrine Surgery