Thyroglossal Duct Cyst

A thyroglossal duct cyst is a cystic remnant of the tract that thyroid cells take during early fetal development from the base of the tongue to its postnatal location in the middle to lower neck. Normally, the remnants of this tract obliterate late in the first trimester, but if cells of this tract persist, they can give rise to a midline cystic remnant known as a thyroglossal duct cyst. Thyroglossal duct cysts can occur anywhere along the thyroglossal duct, but are most commonly found at or below the level of the hyoid bone in the upper neck. Cells of the thyroglossal duct cyst secrete mucus which can gradually cause the cyst to grow.

Presentation

Thyroglossal duct cysts are the most common form of congenital cysts of the neck. Two-thirds are diagnosed before age 30, half present in early childhood. They are often identified by a round, firm, midline upper neck mass. The cyst moves with swallowing or sticking out the tongue. Children with a thyroglossal duct cyst are usually asymptomatic, but may complain of some tenderness to palpation. Approximately a third present with infection which manifests as redness, tenderness, an increase in size, and occasionally spontaneous drainage. Very rarely, the cyst may cause difficulty swallowing or breathing.

Diagnosis

A thyroglossal duct cyst is usually diagnosed during a history and physical. It occasionally follows an upper respiratory illness. Diagnostic tests may include blood work to assess thyroid function and an ultrasound to assess the characteristics of the lesion and to document the presence of a normal thyroid gland.

Treatment?

  • If the thyroglossal duct cyst is infected, antibiotics will be given to control the infection. Surgery will not take place until the infection is resolved.
  • Surgery is the most common approach to remove or excise the cyst as well as its embryonic connection to the base of the tongue. This requires removal of the central portion of the hyoid bone and is called the Sistrunk procedure. Without removal of the tract, the recurrence rates were very high (up to 70%). Removal of the tract through the hyoid bone is associated with a decrease in the rates of recurrence to 2-4%. There are no known consequences due to removal of the hyoid bone. After resection, the specimen is sent to pathology to confirm the diagnosis.