Thyroglossal duct cyst

The cyst can be located anywhere from the foramen caecum (base of tongue) (Fig.1) to the suprasternal region: 25% occur in the suprahyoid region, 15% at the level of the hyoid and 65% below the level of the hyoid bone. When it occurs above the hyoid bone it is often in a midline location. If infrahyoid, the cyst can be midline or slightly off-midline in location.

The cyst presents as a fluctuating and painless cervical mass unless it becomes infected. The mass moves with the protrusion of the tongue. The most frequent complication is the formation of a fistula, usually after trauma or infection.

Ultrasonography will demonstrate a midline, anechoic, hypoechoic mass or, if infected, a heterogeneous cyst-like mass. Echogenic thyroid tissue may be found in the cyst. CT and MRI show an uncomplicated cyst as a well circumscribed lesion of uniform density and intensity.

Ectopic or lingual thyroid can on occasion mimic a thyroglossal duct cyst. It is imperative to confirm the thyroid position, by either ultrasound or scintigraphy, prior to surgery .

LT