Thyroglossal Duct Cyst

  • Etiology:
    — Cystic expansion of thyroglossal duct remnant between base of tongue and thyroid bed
    — Occur along path of thyroid descent from foramen cecum at tongue base to lower neck
  • Imaging:
    — If suprahyoid: Can be in tongue or midline
    — If infrahyoid: Can be off-midline closely related to strap muscles (sternohyoid, sternothyroid, thyrohyoid, omohyoid muscles)
  • Imaging US:
    — Moves with tongue protrusion and swallowing if at hyoid bone
  • Imaging CT:
    — Low density
    — No contrast enhancement unless infected
  • Imaging MRI:
    — Well defined cyst along course of thyroglossal duct or inseparable from strap muscle
    — T1WI: Hypointense
    — T1WI post contrast: Thick rim enhancement when infected
    — T2WI: Hyperintense
  • DDX:
  • Complications: Infection
  • Treatment: Surgical
  • Clinical:
    — Most common congenital neck mass
    — Most common midline cystic neck mass in children
    — 90% present before age of 10
    — Presents as painless lump in neck
    — Location – 25% suprahyoid and 50% hyoid and 25% infrahyoid

Radiology Cases of Thyroglossal Duct Cyst

US of thyroglossal duct cyst
Transverse (above) and sagittal (below) US of the neck shows a cyst in the midline of the neck that moved in relationship with tongue protrusion.

Radiology Cases of Thyroglossal Duct Cyst Containing Ectopic Thyroid

I-123 scan of thyroglossal duct cyst containing thyroid tissue
Anterior view of a I-123 thyroid scan shows tracer uptake in a single midline region that corresponds directly to the patient’s midline neck mass, without any demarcation of the lobes of the thyroid. There was no other thyroid uptake in the neck.

Clinical Cases of Thyroglossal Duct Cyst

Clinical Cases of Thyroglossal Duct Cyst Containing Ectopic Thyroid

Clinical image of thyroglossal duct cyst
AP (above) and lateral (below) clinical images show a large mass in the midline of the neck.

Surgery Cases of Thyroglossal Duct Cyst

Surgery Cases of Thyroglossal Duct Cyst Containing Ectopic Thyroid

Surgery image of thyroglossal duct cyst
Surgical images show the mass (between the forceps) which had been intimately adherent to the mid-point of the hyoid bone and a central tract extending from the mass up to the foramen cecum.

Histopathology Cases of Thyroglossal Duct Cyst

Histopathology Cases of Thyroglossal Duct Cyst Containing Ectopic Thyroid

Histopathology image of thyroglossal duct cyst
Histopathological image H&E stained section shows a fibrous-walled cyst lined by ciliated, respiratory type epithelium (on the left). Scattered, small thyroid follicles (some containing eosinophilic colloid) are noted in the adjacent fibroconnective tissue (on the right).