Definition of Thyroglossal cyst

Thyroglossal cyst: A fluid-filled sac present at birth in the midline of the neck. A thyroglossal cyst is a congenital malformation (a birth defect). It results from incomplete closure of a segment of the thyroglossal duct, a tube-like structure that normally closes as the embryo develops. Also called a thyroglossal duct cyst or a thyrolingual cyst.

Common Misspellings: thyroglossal cysct, thyroglossal sist