The thyroglossal duct occurs along the course of the thyroid as it descends from the tongue to the lower neck during intrauterine development. While the duct normally disappears, a remnant may persist and give rise to a cystic dilatation.


The cyst is usually identified in a preschool child but it may be detected first in adolescence or early adulthood.


Clinical features of a thyroglossal duct cyst:

(1) occurs within 2 cm of the midline

(2) most common near the hyoid bone but rarely may occur in the tongue or in the suprasternal region

(3) at birth there is no sinus opening, but one may develop if the cyst becomes infected and drains, usually in the midline of the neck

(4) tends to be soft, smooth and nontender (if not infected)


A lingual cyst may move when the tongue is protruded or if the patient swallows.


Differential diagnosis:

(1) lingual thyroid: The thyroid fails to migrate to the lower neck. Resection of the mass can result in severe hypothyroidism. It is therefore necessary to perform a thyroid scan prior to surgery on a lingual mass; in a lingual thyroid there will be no uptake in the neck.

(2) dermoid cyst: These rarely becomes infected but can rupture. They do not move with tongue protrusion or swallowing.


To read more or access our algorithms and calculators, please log in or register.