Thyroglossal duct cyst (TGDC)

• The most common congenital cervical anomaly.

• 7% of population prevalence.

• They form in midline anywhere along the thyroid's route of migration between the tongue and the inferior neck.

• A TGDC is an embryologic remnant that forms due to the failure of closure of the thyroglossal duct

• It closely related to hyoid bone.

About 20% to 25% at the level of suprahyoid,

15% to 20% at the level of hyoid,

25% to 65 % present at the infrahyoid level.

Picture 1: Well defined thin wall <2mm cystic lesion contain fine echo no solid part thin partial septum in 53y old female at level of hyoid bone, 38*27*28mm.

Picture 2: A well defined about 2mm wall thickness 21*15*12mm cystic nodule seen in midline of neck level of hyoid bone with internal debris and mild peripheral vascularity , complicated /infected TGDC.

Picture 3: Well defined thin wall cystic nodule in between hyoid bone an upper margin of thyroid cartilage 20*14*9mm, in 40y old lady