All you need to know about thyroglossal duct cysts
The cyst forms in tissue that is sometimes left over from the development of the thyroid gland.
Thyroglossal cysts are present at birth and often occur in children.
- The cyst is usually a painless, soft, round lump in the front center of the neck.
- They will typically move when the person swallows or sticks their tongue out.
- Surgical removal of the cysts helps prevent recurrence and infection.
- They are often diagnosed in preschool-aged children or during mid-adolescence.
How they form
Thyroglossal duct cysts are usually diagnosed in childhood.
Image credit:Klaus D. Peter, Gummersbach, Germany, (2008, December 10.)
During fetal development, the thyroid gland is located at the back of the tongue.
It naturally migrates down the neck, passing through the hyoid bone.
The hyoid bone anchors the tongue and is situated at the root of the tongue in front of the neck.
As the thyroid gland descends, it forms a small channel called the thyroglossal duct.
This duct usually disappears once the thyroid gland reaches its final position in the neck. Sometimes part of the duct remains and leaves a pocket. A thyroglossal cyst will form when fluid collects in this pocket.
Aside from the presence of a lump, sometimes mucus may seep out of a small opening in the skin near the lump. If the cyst becomes infected, it can become tender, red and swollen.
Some people with a thyroglossal cyst may find it difficult to swallow or to breathe. Sometimes people who have thyroglossal cysts can experience recurring infection, excessive swelling, or pressure symptoms.
Surgery may be an option when any of these symptoms occur.
Thyroglossal duct cysts may have no symptoms at all and can go unnoticed until they become infected.
An ultrasound scan may be required to diagnose the thyroglossal cyst.
A cyst often appears after an upper respiratory infection because this causes them to enlarge and to become painful.
Symptoms of thyroglossal cysts can be attributed to other medical conditions, and a conclusive diagnosis is necessary. Diagnostic tests for thyroglossal duct cysts may include any of the following:
- blood test
- ultrasound examination
- thyroid scans
- fine needle aspiration
- X-rays with a contrast dye
Once diagnosed, the doctor may refer the affected person to an ear, nose, and throat specialist for treatment.
Surgeons usually remove thyroglossal duct cysts for the comfort of the person. Removal also allows for further investigation and diagnosis. In rare cases, this can include cancer.
Treatment will depend on the person's age and general health. It will also depend on the severity of the symptoms.
Surgery is a standard treatment option. The Sistrunk procedure is the most effective in removing thyroglossal cysts so that they do not reoccur. A thyroglossal duct cyst has only a small chance of recurring, and that is if any of the tissue remains after removal.
Doctors may treat infected thyroglossal duct cysts with antibiotics, even if surgery is being planned. Infection before surgery can make the removal more difficult and increases the chance of recurrence.
What to expect during surgery
During the Sistrunk procedure, a surgeon makes an incision in the front of the neck, over the swelling. They then remove the thyroglossal tract up to its root, including a segment of the hyoid bone.
The Sistrunk procedure takes about 90 minutes and usually takes place under general anesthesia. The tissue that is removed is sent to a pathology laboratory to confirm the diagnosis.
A Sistrunk procedure may include an overnight stay in a hospital. A doctor will prescribe painkillers according to individual requirements. The level of pain or discomfort felt after the operation varies from person to person.
Risks and complications
The surgeons should explain the potential risks involved before performing the surgery. Follow-up appointments are common, to ensure the site of the surgery is healing properly.
Complications after surgery range from mild to severe and may include the following:
- Bleeding: The risk of bleeding is usually slight. Blood thinners taken for other medical conditions can increase this risk, and a person must tell the doctor before surgery.
- Clotting: If bleeding results in a blood clot forming under the wound, a small procedure may be necessary to stop the bleeding.
- Fistula: Sometimes fluid can leak from the site after surgery. This is called a fistula and may need further treatment.
- Infection: If the wound is kept clean, the risk of infection is minimal. Infection, if it does occur, can cause acute pain, airway obstruction, and problems with swallowing.
- Scarring: There will be a surgical scar on the front of the neck. Some people develop hypertrophic scarring and keloids. This is where excessive scar forms and is sometimes itchy.
- Nerve damage: During surgery, there is a very small risk of damage to the nerve that is linked to the movement of the tongue.
- Hyperthyroidism: If the cyst contained functional thyroid tissue, then there is a small risk that less thyroid hormone will be produced after it has been removed.
Symptoms can arise from the swelling itself or post-operative complications.
It is best to rest for up to 3 weeks following surgery. Avoid driving for 2 weeks and long-haul flights for 2 months. If non-dissolvable sutures are used, then they will have to be removed after a week.
At some point after the surgery, a person will need to attend a follow-up appointment to monitor post-operative recovery. In the meantime, call the doctor if there is any fever, swelling, redness, drainage, or pain.