What is a thyroglossal duct cyst?

A thyroglossal duct cyst happens when your thyroid, a large gland in your neck that produces hormones, leaves behind extra cells while it’s forming during your development in the womb. These extra cells can become cysts.

This kind of cyst is congenital, meaning that they’re present in your neck from the time you’re born. In some cases, the cysts are so small that they don’t cause any symptoms. Large cysts, on the other hand, can prevent you from breathing or swallowing properly and may need to be removed.

The most visible symptom of a thyroglossal duct cyst is the presence of a lump in the middle of the front of your neck between your Adam’s apple and your chin. The lump usually moves when you swallow or stick your tongue out.

The lump may not become apparent until a few years or more after you’re born. In some cases, you may not even notice a lump or know the cyst is there until you have an infection that causes the cyst to swell.

Other common symptoms of a thyroglossal duct cyst include:

  • speaking with a hoarse voice
  • having trouble breathing or swallowing
  • an opening in your neck near the cyst where mucus drains out
  • feeling tender near the area of the cyst
  • redness of the skin around the area of the cyst

Redness and tenderness may only happen if the cyst gets infected.

Your doctor may be able to tell if you have a thyroglossal duct cyst simply by examining a lump on your neck.

If your doctor suspects that you have a cyst, they may recommend one or more blood or imaging tests to look for the cyst in your throat and confirm the diagnosis. Blood tests can measure the amount of thyroid-stimulating hormone (TSH) in your blood, which indicates how well your thyroid is working.

Some imaging tests that may be used include:

  • Ultrasound: This test uses sound waves to generate real-time images of the cyst. Your doctor or an ultrasound technician covers your throat in a cool gel and uses a tool called a transducer to look at the cyst on a computer screen.
  • CT scan: This test uses X-rays to create a 3-D image of the tissues in your throat. Your doctor or a technician will ask you to lie flat on a table. The table is then inserted into a donut-shaped scanner that takes images from several directions.
  • MRI: This test uses radio waves and a magnetic field to generate images of the tissues in your throat. Like a CT scan, you’ll lie flat on a table and remain still. The table will be inserted inside a large, tube-shaped machine for a few minutes while images from the machine are sent to a computer for viewing.

Your doctor may also perform fine needle aspiration. In this test, your doctor inserts a needle into the cyst to extract cells that they can examine to confirm a diagnosis.

Normally, your thyroid gland begins developing at the bottom of your tongue and travels through the thyroglossal duct to take its place in your neck, right below your larynx (also known as your voice box). Then, the thyroglossal duct vanishes before you’re born.

When the duct doesn’t go away completely, the cells from the leftover duct tissue can leave openings that become filled with pus, fluid, or gas. Eventually, these matter-filled pockets can become cysts.

If your cyst has a bacterial or viral infection, your doctor will prescribe antibiotics to help treat the infection.

Thyroglossal duct surgery

Your doctor will likely recommend surgery to remove a cyst, especially if it’s been infected or is causing you to have trouble breathing or swallowing. This type of surgery is called the Sistrunk procedure.

To perform the Sistrunk procedure, your doctor or surgeon will:

  1. Give you general anesthesia so that you can stay asleep during the whole surgery.
  2. Make a small cut on the front of the neck to open the skin and muscles above the cyst.
  3. Remove the cyst tissue from your neck.
  4. Remove a small piece from the inside of your hyoid bone (a bone above your Adam’s apple that’s shaped like a horseshoe), along with any remaining tissue of the thyroglossal duct.
  5. Close the muscles and tissues around the hyoid bone and areas that were operated on with stitches.
  6. Close the cut on your skin with stitches.

This surgery takes a few hours. You may need to stay in the hospital overnight afterward. Take a few days off work or school, and make sure a friend or family member is available to take you home.

While you’re recovering:

  • Follow any instructions your doctor gives you to take care of the cut and the bandages.
  • Go to a follow-up appointment that your doctor schedules for you.

Most cysts are harmless and won’t cause any long-term complications. Your doctor may still recommend removing a harmless cyst if it’s causing you to feel self-conscious about the appearance of your neck.

Cysts may grow back even after they’ve been fully removed, but this happens in less than 3 percent of all cases. Cyst surgery can also leave a visible scar on your neck.

If a cyst grows or become inflamed because of an infection, you may not be able to breathe or swallow properly, which can be potentially harmful. Also, if a cyst gets infected, it may need to be removed. This usually happens after the infection has been treated.

In rare cases, these cysts can become cancerous and may need to be removed immediately to stop the cancerous cells from spreading. This happens in less than 1 percent of all cases of thyroglossal duct cysts.

Thyroglossal duct cysts are usually harmless. Surgical cyst removal has a good outlook: over 95 percent of cysts are fully cured after surgery. The chance of a cyst returning is small.

If you notice a lump in your neck, see your doctor right away to make sure the lump isn’t cancerous and to have any possible infections or overgrown cysts treated or removed.