Cysts, sinuses, and fistulas are the commonest forms of clinical lesions which occur in the thyroglossal duct tract. Malignant tumors are considered a rare entity.
Embryologically, this tract begins as a midline hollow, stalk-like evagination of the floor of the pharynx between the ventral ends of the first and second bronchial arches. This descends in the midline of the neck, prior to fusion of the arches which will form the tongue substance, and proceeds through tissue which will later form the hyoid bone. It terminates and gives origin to pyramidal lobe and a portion of the isthmus of the thyroid gland.
The high columnar epithelial lining degenerates and disappears. Persistent tracts may show a variety of cellular lining anywhere from a high columnar to a squamous pattern. It is not uncommon to find microscopically identifiable bits of thyroid tissue in the walls of persistent tracts. Any one of the above