Thyroglossal Duct Cyst (Fluid-filled midline structure caused by an abnormality on the migration of the thyroid gland)

     
In the fetus the thyroid gland originally forms at the base of the tongue. Early in fetal life it then "migrates" or moves from the base of the tongue inferiorly to end up at the base of the neck overlying the airway (trachea). Sometimes when the thyroid migrates it drags with it some of the lining of the pharynx which can persist as a tract with a cyst at its base along the route of migration of the thyroid gland (see the figure). This then produces a thyroglossal duct cyst which is the result of accumulation of a gelatin-like material secreted by the lining of the cyst or tract. The tract from the base of the tongue can travel through, or immediately in front of, or behind the hyoid bone. The main risk of a thyroglossal duct cyst is that it can become infected by bacteria from the mouth traveling through the tract to the cyst.
  • A thyroglossal cyst usually appears between the second to 10th year of life.
  • It is found equally in both sexes.

     
Common Signs and Symptoms:
 
     
  • The cyst is seen as an asymptomatic midline neck mass often around the hyoid bone
  • The cyst is round and firm with no external opening
  • It moves up when the tongue is stuck out of the mouth or with swallowing
  • Occasionally it can be seen to one side or other of the breathing tube
  • Bacteria from the mouth may infect the thyroglossal duct cyst through the thyroglossal duct tract causing sudden swelling of the cyst and redness or tenderness in the area of the cyst.

     
Treatment:
 
     
  • Surgical excision is recommended unless infection is present.
  • Uncomplicated excisions and postoperative course permit discharge from the hospital several hours after the procedure. Overnight stay may be indicated if there is any hint of airway problems suspected or a drain is placed during the procedure.

Information provided from Child Health A to Z, Children's Hospital Boston web site www.childrenshospital.org