Intra-laryngeal ectopic thyroid tissue. Report of one case and review of the literature

A Ectopic thyroid is any thyroid tissue not located in his normal anatomic situation. There have been described four general groups within the upper aerodigestive tract: lingual, sublingual, thyroglossal and intralaryngotracheal. Intralaryngotracheal thyroid tissue is rare and constitute 7 per cent of all intratracheal tumours, and it represents a problem of diagnosis and management. The controversy about the genesis of this tumours remains. There are two established theories: "the malformation theory" and "the ingrowth theory". These tumours affect more frequently adult female. Intralaryngotracheal thyroid have been mainly reported on the posterior-left wall of the trachea. The most common clinical feature is stridor due to progressive upper airway obstruction. Up to 75% of the intralaryngotracheal goiters are associated with and external goiter. This paper reports a case of ectopic subglotic thyroid in a 42 year-old-female. The embryology, diagnosis and management of this tumours are discussed.