Figure 2d.  Persistent thyroglossal duct sinus tract in a 5-year-old boy who had undergone two partial resections for a thyroglossal duct cyst in the preceding 9 months. (a) Photograph of the lower neck shows a fistulous ostium with a transverse surgical scar on both sides. (b) CT scan obtained after ethiodized oil was injected into the fistula shows focal collection of the contrast agent in the region of the foramen cecum (arrow). (c, d) CT scans obtained at lower levels show the contrast material–enhanced path of the thyroglossal duct along the anterior surface of the hyoid bone (arrow in c) and inferiorly to the skin ostium near the pyramidal lobe of the thyroid (arrow in d). (e) Photograph of the surgical specimen reveals entire length of the fistulous tract.