Overview
During development, the thyroid gland forms at the base of the tongue and moves down to its final position. After it reaches its final position, a path is left behind known as the thyroglossal (‘thyro’ – thyroid, ‘glossal’ – tongue) duct which normally closes. If the thyroglossal duct persists, it can fill with fluid and form a thyroglossal cyst.
One of the main complications of a thyroid cyst is infection.
Epidemiology
- Thyroglossal cysts are the most common neck congenital abnormality
- Thyroglossal cysts may be found in up to 7% of the population
Presentation
Thyroglossal cysts present as a fluctuant swelling in the midline of the neck that moves upwards with protrusion of the tongue.
If infected, it may become tender, erythematous, and warm. There may be associated dysphagia and airway obstruction.
Investigations
Overview
Thyroglossal cysts can be diagnosed with a thorough history and neck examination, including an examination of the thyroid gland. The following tests may be performed:
- Thyroid function tests (TFTs):
- To screen for thyroid dysfunction
- Ultrasound and CT scanning:
- The initial investigation of choice – identifies the cyst
Management
Overview
Thyroglossal cysts are surgically removed because:
- This can provide histological confirmation of the diagnosis
- Infection can occur which can also carry the risks of complications such as dysphagia and airway obstruction
- They can cause cosmetic problems
- In rare cases, malignancy can occur
