Thyroglossal Duct Cysts

These are lumps found in the front of the neck in the midline. They are formed due to a persistent thyroglossal duct.

During the development of the thyroid gland before birth, the thyroid gland in the foetus migrates from the bottom of the tongue to its final position in the neck. The path that the thyroid gland takes during its descent into the neck usually disappears, but sometimes persists as a persistent thyroglossal duct.

This persistent duct can give rise to cysts (fluid-filled lumps) or sinuses (blind-ending tracts that lead to the skin).

How do Thyroglossal cysts present?

These lumps usually are hemispherical lumps that appear in the front of the neck in the midline. These lumps tend to move with swallowing and protrusion of the tongue. These lumps are usually painless, however they can become infected and if they do, they may become painful and red.

What tests will I have to undergo?

1. Thyroid function tests
   This is a blood test where the levels of your thyroid hormones (T4) and thyroid-stimulating hormone (TSH) are measured. If your levels of thyroid hormones are too high (hyperthyroidism), you may experience symptoms such as palpitations, feeling hot easily, irritability, diarrhoea, weight loss and increased appetite.
   
   If your thyroid hormone levels are too low (hypothyroidism) you may feel easily tired and lethargic, gain weight easily, constipation, memory loss and feeling cold easily.
   
   Thyroid-related diseases cannot be excluded even if the thyroid function test is within normal ranges.
2. Ultrasound Scan
   In this scan, sound waves are used to produce a picture of your thyroid gland and neck structures on a screen. The ultrasound scan is very useful for evaluating thyroid nodules and to look for features that may indicate that the thyroid nodule is suspicious for cancer. It is also useful for looking for any enlarged lymph nodes in the neck. This scan is painless and there is no ionising radiation involved.
3. Fine-needle Aspiration Cytology (FNAC)
   Your doctor may advise you to undergo a biopsy to evaluate the lump if he feels that it is needed.
   
   A fine-needle aspiration biopsy is a procedure where the doctor will pass a small needle through the lump to aspirate some cells for the lump for further testing. These cells will be examined under a microscope to look for signs of cancer.
   
   This biopsy is often done using an ultrasound to guide the doctor to biopsy the correct place.

What treatment will I undergo?

These lumps are usually treated with surgery. The operation to remove them is called a Sistrunk operation. It involves removal of the lump as well as the middle part of one of the bones in the front of the neck called the hyoid bone which the lump is usually attached to.