Thyroglossal Duct Cyst

Background

A thyroglossal duct cyst commonly presents as a midline neck swelling. 

A thyroglossal duct cyst develops when your thyroid, leaves behind extra cells while migrating from the base of the tongue down to the final position in the lower neck during your development in the womb. These extra cells produce fluid

Thyroglossal cysts are prone to infection resulting in an increase in size and can become quite painful. A large cyst can interfere with swallowing (dysphagia)  and cause hoarseness. Most (2/3) patients with thyroglossal cysts have ectopic thyroid tissue within the cyst.

Classically, a thyroglossal cyst can be diagnose on physical examination by observing the movement of the cyst/lump when the patient is swallowing and sticking out their tongue.

The majority of thyroglossal cysts are detected during childhood but it can become apparent at any age. Most thyroglossal duct cysts occur around the hyoid bone, a thin U-shaped bone lying high in the neck.

Less frequently cysts may also occur within the tongue.

Special imaging

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.

The Surgical procedure

Surgical removal of the thyroglossal cyst is the only treatment option available. The operation is called the Sistrunk procedure, named for the surgeon who first described it.

Most cases can be performed with a same day discharge although patients may occasionally stay one night in hospital. 

Surgery is performed under a short general anaesthetic and most operations are performed in under 1 hour by our experienced surgical team

To reduce the risk of recurrences, it is important to do the following during the operation:

·         removing the cyst completely,

·         Removing the central part of the hyoid bone where the cyst is attached to.

·         Removing the part of the duct in the base of the tongue above the hyoid bone.

How the Sistrunk Procedure is Performed

1.      A transverse incision is made in the neck at the level of the hyoid bone. The incision is approximately 3-4cm in length.

2.      The skin and the platysma muscle are elevated to expose the cyst

3.      The cyst is then dissected away from the surrounding muscles and tissues up to the level of the hyoid bone.

4.      The thyroglossal duct track is followed down up to the thyroid gland and divided at the lower end from the thyroid.

5.      Above the cyst, a section of the center of the hyoid  measuring about 10-15mm is removed together with the cyst and tract.

6.      Above the hyoid bone up to the level of the back of the tongue, a core of tissue is then removed as needed to ensure no part of the duct is left behind.

7.      In exceptional cases, with the duct stretching all the way up to the tongue surface, the foramen cecum is removed.

8.      If the tract extended to the tongue base and needed to be removed the opening into the mouth would be closed. Then the tongue muscles are sutured, and the tissues at the cut ends of the hyoid bone drawn together with sutures.

9.      Very occasionally a small drain is left in the wound and the skin is closed over it using absorbable sutures.

Possible Complications

As with all surgical procedures, there are potential risks and complications associated with this procedure. Complications are very rare but may include nerve injury, airway injury, thyroglossal cyst recurrence and the development of a haematoma or abscess which may require further surgical intervention.  Other minor complications include superficial surgical site infections, small abscesses around the sutures, seromas and dehiscence of the wound. All these complications can be easily managed effectively.

The risk of developing complications is kept low by employing a meticulous surgical technique and by identifying key anatomical landmarks in order to reduce the risk of inadvertent injury to surrounding structures.

Recurrence

Reported recurrence rates following the Sistrunk procedure are low, between 0 and 8%.

Follow-up care

On discharge a mild anaelgesic will be prescribed.  You do not have to take it if you have no pain.  

Your wound will ether have a small, watertight dressing or be covered with special surgical glue to seal the wound.

You may shower or wash, and the wound may get wet.

We will schedule a follow-up appointment for 4-6 weeks after the procedure.

When to call the doctor

Please call our unit at 021 939 7790 if any of the following symptoms occur:

• Fever (a temperature of 38 degrees or higher)
• Any signs of infection, including redness, swelling or pain
• Any drainage from the incision
• Any pain that is not controlled with the prescribed pain medicine
• A mass or lump in the center of the neck.