Editing Thyroid (section)

====Congenital====
A [[persistent thyroglossal duct]] is the most common clinically significant [[birth defect]] of the thyroid gland. A persistent sinus tract may remain as a vestigial remnant of the tubular development of the thyroid gland. Parts of this tube may be obliterated, leaving small segments to form [[thyroglossal cyst]]s.<ref name="LANGMAN" /> Preterm neonates are at risk of hypothyroidism as their thyroid glands are insufficiently developed to meet their postnatal needs.<ref>{{cite journal | vauthors = Berbel P, Navarro D, Ausó E, Varea E, Rodríguez AE, Ballesta JJ, Salinas M, Flores E, Faura CC, de Escobar GM | display-authors = 6 | title = Role of late maternal thyroid hormones in cerebral cortex development: an experimental model for human prematurity | journal = Cerebral Cortex | volume = 20 | issue = 6 | pages = 1462–75 | date = June 2010 | pmid = 19812240 | pmc = 2871377 | doi = 10.1093/cercor/bhp212 | url = }}</ref> In order to detect hypothyroidism in newborn babies, to prevent growth and development abnormalities in later life, many countries have [[newborn screening]] programs at birth.<ref>{{cite journal | vauthors = Büyükgebiz A | title = Newborn screening for congenital hypothyroidism | journal = Journal of Clinical Research in Pediatric Endocrinology | volume = 5 Suppl 1 | issue = 4 | pages = 8–12 | date = 15 November 2012 | pmid = 23154158 | pmc = 3608007 | doi = 10.4274/Jcrpe.845 }}</ref>

Infants with thyroid hormone deficiency ([[congenital hypothyroidism]]) can manifest problems of physical growth and development as well as brain development, termed [[cretinism]].{{sfn|Greenspan's|2011|p=164}}<ref name=":1" /> Children with congenital hypothyroidism are treated supplementally with [[levothyroxine]], which facilitates normal growth and development.<ref>{{cite journal | vauthors = Rose SR, Brown RS, Foley T, Kaplowitz PB, Kaye CI, Sundararajan S, Varma SK | title = Update of newborn screening and therapy for congenital hypothyroidism | journal = Pediatrics | volume = 117 | issue = 6 | pages = 2290–303 | date = June 2006 | pmid = 16740880 | doi = 10.1542/peds.2006-0915 | doi-access = free | author5 = Public Health Committee | author6 = Lawson Wilkins Pediatric Endocrine Society | author3 = American Thyroid Association }}</ref>

Mucinous, clear secretions may collect within these cysts to form either spherical masses or fusiform swellings, rarely larger than 2 to 3&nbsp;cm in diameter. These are present in the midline of the [[neck]] anterior to the [[trachea]]. Segments of the duct and cysts that occur high in the neck are lined by [[stratified squamous epithelium]], which is essentially identical to that covering the posterior portion of the [[tongue]] in the region of the foramen cecum. The disorders that occur in the lower neck more proximal to the thyroid gland are lined by epithelium resembling the thyroidal acinar epithelium. Characteristically, next to the lining epithelium, there is an intense lymphocytic infiltrate. [[superinfection|Superimposed infection]] may convert these lesions into abscess cavities, and rarely, give rise to cancers.{{citation needed|date=September 2011}}

Another disorder is that of [[thyroid dysgenesis]] which can result in various presentations of one or more [[ectopia (medicine)|misplaced]] accessory thyroid glands.{{sfn|Gray's Anatomy|2008|pp=462–4}} These can be asymptomatic.