abnormal thyroid gland development abnormal thyroglossal duct morphology MP:0013235 MPheno.ontology abnormal ductus thyroglossus morphology abnormal thyrolingual duct morphology any structural anomaly of the embryological anatomical structure that forms an open connection between the initial area of development of the thyroid gland and its final position; it is located exactly midline, between the anterior 2/3rds and posterior 1/3rd of the tongue; this duct normally atrophies and closes off as the foramen cecum before birth