1882
A fibrous cyst that forms from a persistent thyroglossal duct.
Usual presentation as a midline palpable neck lump in the region of the hyoid bone.
The most common locations is midline or slightly off midline, between the isthmus of the thyroid and the hyoid bone or just above the hyoid bone.
75% present as midline swellings, and the remainder can be found as far lateral as lateral tip of the hyoid bone.
Can develop anywhere along a thyroglossal duct, including the tongue or the floor of the mouth.
The cyst moves upwards with protrusion of the tongue, because of its attachment to the tongue.
Associated with an increased incidence of ectopic thyroid tissue.
It is usually painless, smooth and cystic.
If it becomes infected, pain can occur.
Large cysts may be associated with difficulty breathing, dysphagia, and/or dyspepsia.
Originates from the foramen cecum at the junction of the anterior two-thirds and posterior one-third of the tongue.
Any part of the duct can persist causing a sinus, fistula or cyst.
The persistence of a duct or sinus can promote oral secretions, which may cause cysts to become infected.
Most fistulae are acquired following rupture or incision of the infected thyroglossal cyst.
Thyroglossal cysts are lined by pseudostratified, ciliated columnar epithelium.
Thyroglossal fistula is lined by columnar epithelium.
Up to half are not diagnosed until adult life., remaining dormant until some kind of stimulus leads to cystic dilation.
Infection of a TDC can sometimes cause transient appearance of a mass or enlargement of the cyst, with periodic recurrences.
TDCs can also spontaneously drain.
Treatment is a surgical resection of the duct to the base of the tongue and removal of the medial segment of the hyoid bone.
Thyroid scans and thyroid function studies are ordered preoperatively to demonstrate that normally functioning thyroid tissue is present.
The cyst is removed if the patient is experiencing difficulty in breathing or swallowing, or if the cyst is infected.
The cyst may also be removed to eliminate the chance of infection or carcinoma, or for cosmetic reasons.
The removal of the central portion of the hyoid bone ensures complete removal of the sinus tract and it is unlikely that there will be a recurrence after such an operation.