Thyroid Nodules

What are thyroid nodules?

Thyroid nodules are abnormal lumps on the thyroid gland, located in the front of your neck. In many cases, you can’t feel them and won’t have any other symptoms. Thyroid nodules are often discovered when your doctor orders imaging tests for another reason.

It’s not unusual to develop thyroid nodules. Up to two-thirds of adults in the U.S. have them, according to a study in JAMA Internal Medicine. Thyroid nodules can affect anyone, but they’re more common in women, older people, and smokers.

Nodules range in size from 1 cm to 4 cm or larger. You may also develop a goiter, which is an enlargement of the thyroid.

Most nodules aren’t cancerous. But according to a study in the New England Journal of Medicine, thyroid cancer occurs in 5% to 15% of nodules, so it’s important that any lumps in your neck are examined by your doctor.

To check for cancer, your doctor will order ultrasound scanning. Depending on the size of the nodules, you may need a needle biopsy, which is when a needle is used to remove tissue from the nodule for testing.

Benign vs. malignant thyroid nodules

There are some signs that doctors look for to help figure out whether a thyroid nodule is benign (non-cancerous) or malignant (cancerous). Benign nodules feel soft to the touch, like a rubber ball, and move easily when being pushed.

Some benign thyroid nodules can start producing large amounts of thyroid hormone, which are called “hot” nodules. They can cause symptoms like:

• Weight loss
• Sweating
• Hot flashes
• Diarrhea

Malignant nodules tend to feel firm and fixed in place. The surrounding lymph nodes may also become enlarged, so you may notice additional lumps in your neck.

Another sign that a nodule is cancerous is if it grows rapidly. You may develop other symptoms as the nodule grows, including:

• Difficulty swallowing
• Neck discomfort
• A sensation that something is stuck in your throat
• Hoarseness (due to damage to the nerve attached to the voice box)

How are thyroid nodules diagnosed?

If your doctor thinks you have thyroid nodules, you will have an ultrasound, which is the most accurate way of identifying the size, number, and other physical features of the nodules.

Based on what the ultrasound shows, your doctor will make a decision about whether the nodules should be biopsied (a sample tissue removed) to look for cancer cells. Nodules with irregular borders, calcifications, and lower density, and those that are taller than they are wide suggest cancer, so they should be biopsied.

A thyroid biopsy is called fine-needle aspiration (FNA). Your doctor will prick the area 3 to 4 times with a small needle to collect thyroid cells. They will be studied under a microscope. Benign nodules can be monitored with repeat ultrasounds at regular intervals, but malignant nodules must be surgically removed.

What is a normal size for thyroid nodules?

Thyroid nodules range in size—your doctor will decide what to do depending on their size.

• Tiny nodules, which are less than 1 cm in diameter. These aren’t usually biopsied.
• Nodules larger than 1 cm with suspicious features are biopsied. Those that are slightly larger and have fewer suspicious features may not be biopsied until they reach a size of 1.5 to 2 cm.
• Very large nodules (greater than 4 cm) are surgically removed. This is necessary because of an increased risk for thyroid cancer and potential to damage nearby structures in the neck.

Nodules of any size that get bigger should also be biopsied.

How to check your thyroid

During your annual exams, your doctor will examine your thyroid to see if it appears enlarged. Your doctor will check the size, texture, and presence of nodules with their fingers. They will ask you to swallow, which raises the thyroid gland higher in the neck and allows them to feel it more easily. They will also feel for enlarged lymph nodes in your neck.

It is not recommended that people do thyroid self-exams at home. Self-exams have not been shown to improve outcomes of thyroid cancer and they may lead to unnecessary worry, diagnostic tests, and invasive procedures.

When to see a doctor and treatment

All thyroid nodules should be examined by your doctor. If you have any of these symptoms—rapid enlargement of your neck, difficulty swallowing, hoarseness—make an appointment with your doctor right away.