Endocrine System Internal Medicine

Thyroglossal duct cysts

Anterior midline neck mass (fibrous cyst) that moves with swallowing or protrusion of the tongue that forms from a persistent thyroglossal duct.

Anterior midline neck mass (fibrous cyst) that moves with swallowing or protrusion of the tongue that forms from a persistent thyroglossal duct.

  • Congenital defect: Degeneration of part of tract → Cystic swelling
  • Tubulodermoid cyst: Lined by pseudostratified, ciliated columnar epithelium


Thyroglossal cyst locations:

Related to the thyroglossal duct
Thyroglossal Duct Cyst locations
Thyroid Clinic Sydney. (2016). Sistrunk Procedure for Thyroglossal Duct Cyst – Thyroid Clinic Sydney. [online] Available at: [Accessed 24 May 2017]
  • Subhyoid (M/C site)
  • On thyroid cartilage (2nd M/C site)
  • Suprahyoid
  • Beneath foramen caecum
  • Mouth floor


  • Painless swelling:
    • Smooth, soft, fluctuant (cystic), non-tender, mobile, transilluminant
    • In the midline, towards the left
    • Moves with deglutition and with tongue protrusion
  • Tugging sensation
    1. The patient opens mouth and keeps lower jaw still.
    2. Examiner holds cyst and patient asked to protrude tongue
    3. Tugging sensation felt
  • Pain & redness
    • If infected
  • Thyroid fossa
    • Empty
      • If thyroid not in normal location
Thyroglossal duct cyst clinical appearance
Thyroglossal duct cyst | By Klaus D. Peter, Gummersbach, Germany – Own work, CC BY 3.0 de,


  • Infection → abscess
  • Thyroglossal fistula
  • Malignancy (Thyroglossal cyst carcinoma)
    • Treatment:
      • Complete thyroidectomy (if rest of thyroid is nodular or shows cold nodule or enlargement of neck nodes or with history of neck irradiation)
      • Node dissection + radioactive iodine therapy with suppressive dose of L thyroxine 0.3 mg OD
Thyroglossal Fistula
Thyroglossal Fistula is an acquired fistula related to the thyroglossal duct. It represents about 15 % of the cases. It is never congenital. The opening is small, midline, and with a crescentic skinfold above it. It moves up with swallowing and with protrusion of the tongue. (a) Thyroglossal fistula with the tongue in place, (b) Upward movement of the fistulous opening with protrusion of the tongue | Themes, U. (2016). Swellings of the Neck. [online] Ento Key. Available at: [Accessed 24 May 2017]


Blood TestBlood testing of thyroid function.
UltrasoundImage capture of the degree of mass and its surrounding tissues.
Thyroid ScanRadioactive iodine or technetium (a radioactive metallic element) is used in this procedure to show any abnormalities of the thyroid.
Fine Needle AspirationThe removal of cells for biopsy, using a needle
Ultrasound image of thyroglossal duct cyst
Ultrasound image of thyroglossal duct cyst | Nevit Dilmen, CC BY-SA 3.0,

Differential diagnosis:

  • Subhyoid bursa
  • Pretracheal lymph node
  • Dermoid cyst
  • Solitary nodule of thyroid – isthmus
  • Submental lymph node
  • Collar stud abscess


Sistrunk operation (prevents recurrence)

Excision of cyst + full tract up to foramen caecum + central part of hyoid bone

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