Ultrasound of Thyroglossal Duct Cyst

In this radiology lecture, we review the ultrasound appearance of thyroglossal duct cyst with two unique cases!

Key teaching points include:

Thyroglossal duct cyst is the most common congenital neck cyst.
Most present before age 18 as a midline, fluctuant neck mass near hyoid bone.
Often asymptomatic unless superinfected = Abscess, draining sinus.
Epithelial-lined cysts caused by failure of normal involution of thyroglossal duct.
Can occur anywhere from foramen cecum of tongue to thyroid gland.
Most are infrahyoid, followed by hyoid and suprahyoid.
Most are midline, but can be paramedian (more likely if infrahyoid).
If infrahyoid, typically embedded in strap muscles.
May move with swallowing and elevates with tongue protrusion.
Presence of normal thyroid gland should be confirmed.
When simple, typically appears as an anechoic midline neck mass near hyoid bone.
Cyst complexity usually due to superinfection: Proteinaceous internal debris and septations, thick irregular walls, increased blood flow and surrounding inflammation.
Solid components may indicate ectopic thyroid or rarely (less than 1% of cases) thyroid cancer (typically papillary subtype).
Tx: Resection of cyst, surrounding tissue along the thyroglossal tract, and midline portion of hyoid bone = Sistrunk procedure.