Definition of Cyst, thyroglossal

1. Atrial Fibrillation Slideshow Pictures
2. Bad Bugs and Their Bites Slideshow
3. Understanding Ulcerative Colitis Slideshow

Cyst, thyroglossal: A fluid-filled sac that is present at birth and located 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.