A thyroglossal duct cyst is a congenital cyst that sits exactly in the midline of the neck, usually at the level of the hyoid bone. It is the most common congenital cause of a midline neck swelling and is mostly noticed in childhood, but it can also appear in adulthood. Its most distinctive feature is that it moves upwards on swallowing and when the tongue is stuck out.
What is a thyroglossal duct cyst?
At the start of development in the womb, the thyroid gland forms at the base of the tongue and descends to its position in the lower front of the neck. The path it follows during this descent is called the thyroglossal duct, and it normally closes and disappears once development is complete. If part of the duct remains open, a fluid-filled cyst can develop at any point between the base of the tongue and the thyroid gland, most often around the hyoid bone. Because the duct passes through or just behind the hyoid bone, the cyst is closely related to this bone.
Symptoms
- A soft lump that does not hurt, in the front midline of the neck, usually above the Adam’s apple
- Upward movement of the lump on swallowing and when the tongue is stuck out1
- Sudden enlargement, redness and pain of the lump during an upper respiratory tract infection1
- If an infected cyst opens onto the skin, a small leaking opening in the midline
- Rarely, a feeling of something catching on swallowing or fullness at the base of the tongue
Diagnosis
On examination, the midline position and movement on swallowing are the typical findings. Ultrasound shows the structure of the cyst and checks whether the thyroid gland is in its normal position; this check matters because, rarely, the tissue thought to be a cyst may be the person’s only functioning thyroid tissue. Magnetic resonance imaging (MRI) or computed tomography (CT) may be requested to see the relationship of the cyst with the hyoid bone and the base of the tongue in detail. If considered necessary, thyroid function is assessed with blood tests; in doubtful cases, a sample may be taken with a fine needle.1,2
Treatment
Thyroglossal duct cysts do not disappear on their own. During an inflamed period, the inflammation is settled first; the treatment is surgery. Removing the cyst alone is not enough; the extension of the duct towards the base of the tongue and the middle portion of the hyoid bone are removed together with the cyst. This method, known as the Sistrunk operation, is the principal way of making recurrence less likely, because it aims to leave no remnant of the duct behind. The operation is performed under general anaesthesia through a horizontal incision placed in a natural skin crease in the midline of the neck.
What to expect after surgery
Mild pain, swelling and temporary tenderness on swallowing are normal after surgery and usually subside within a few days. Removal of a small piece of the hyoid bone is usually not expected to affect speech or swallowing permanently. After a short period of observation, eating begins with soft foods and daily life is resumed. The scar usually fades over time. The removed tissue is examined by a pathologist, because in rare cases (fewer than 1 in 100) a cancer develops in a thyroglossal duct cyst.1,2 When the cyst and duct are removed completely, recurrence becomes less likely; performing the operation during a period free of inflammation is important in this respect.1,2
When should you see a doctor?
- If you have noticed a persistent lump in the midline of your neck
- If the lump repeatedly enlarges with infections
- If there is redness, pain or discharge over the lump
- If difficulty swallowing or breathing accompanies it
Frequently asked questions
What is a thyroglossal duct cyst?
A thyroglossal duct cyst is a congenital cyst that sits exactly in the midline of the neck, usually at the level of the hyoid bone. It forms when part of the duct that the thyroid gland follows during its descent in the womb remains open; it moves upwards on swallowing and when the tongue is stuck out.
How is a thyroglossal duct cyst diagnosed?
On examination, the midline position of the lump and its movement on swallowing are the typical findings. Ultrasound shows the structure of the cyst and checks whether the thyroid gland is in its normal position; MRI or CT may be requested to see the relationship of the cyst with the hyoid bone and the base of the tongue in detail.
Does a thyroglossal duct cyst go away on its own?
No. The cyst is a congenital remnant; it is treated by removing it surgically together with its duct, which makes recurrence less likely.
Does removing part of the hyoid bone during surgery affect speech?
Only the small middle portion of the hyoid bone is removed; this is usually not expected to affect speech, swallowing or neck movements permanently.
Does this cyst affect the thyroid gland?
The cyst is a structure separate from the thyroid gland and usually does not disturb its function. Before surgery, imaging checks whether the thyroid gland is in its normal position and healthy.
References
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ENT UK. Thyroglossal duct cyst [Internet]. London: ENT UK; 2024 Jun 3 [cited 2026 Oct 5]. Available from: entuk.org ↩
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Amos J, Sutton AE, Shermetaro C. Thyroglossal duct cyst. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 [cited 2026 Oct 5]. Available from: ncbi.nlm.nih.gov ↩
This page is general information. Decisions about diagnosis and treatment are made for you personally, and only after an examination. If you have symptoms, see a doctor.