What congenital anomaly arises from the formation of the thyroid gland?a. The thyroid isthmus
The medial thyroid anlage descends from the base of the tongue through a channel called the thyroglossal duct at week 3 to 4 of gestation. The duct normally closes after its descent, but may remain patent and is susceptible to secondary infection and dilatation, referred to as a thyroglossal duct cyst. Removal is accomplished with the Sistrunk operation which also removes the central portion of the hyoid bone.