Thyroglossyl Duct Remnants are common midline neck lumps in children.
Thyroglossyl Duct Cyst
Thyroglossyl duct cysts are one of the most common lesions in the midline of the neck. It is rare for these lesions to present during the newborn period, even though they are of embryonic origin. Preschool-age is the most common age for these lumps to be found. Thyroglossyl remnants produce midline masses at the base of the tongue down to the pyramid lobe of the thyroid gland. The thyroid develops in the foramen cecum, which develops caudal to the central tuberculum impar (pharyngeal buds).
The hyoid bone is developing form the second branchial arch at this time. The thyroid gland develops between weeks 4 and 7 of gestation and descends into its pretracheal position. Unlike sinuses, thyroglossyl duct cysts never have a primary external opening because the thyroglossyl does not reach the surface of the neck. A cyst can be found anywhere down the migratory course of the thyroglossyl tract in the neck. The cysts will occasionally attach to the pyramida lobe or intrathyroidal. Later, they can break through the skin as an infection.
A lingual thyroid is the complete failure of the thyroid migration, which is located beneath the foramen cecum at the base of the tongue. Rarely, patients with thyroglossyl duct cysts have inadequate thyroid tissue, so symptoms of hypothyroidism (low energy, lethargy, etc) after surgery should be evaluated with thyroid function testing.
Thyroglossyl cysts are classically located below the hyoid bone. The cysts rarely are suprasternal in location. The initial sign of the thyroglossyl cyst is a mass in the midline of the neck. Thyroglossyl duct cysts on physical examination feel smooth, soft, and nontender. Lesions should be surgically excised before they get infected. Excision of infected lesions is difficult and it is often better to drain the abscess and delay definative surgery.
Thyroglossyl duct cysts are treated complete excision of the cyst and its tract, upward to the base of the tongue. Excising the central portion of the hyoid bone in necessary to prevent recurrence.