Lateral Ectopic Thyroid Goiter with a Normally Located Thyroid

Abstract

Laterally located ectopic thyroid tissue is a very rare condition. Ectopic thyroid tissues can undergo the same pathological changes as a normally located thyroid gland. Ectopic thyroid goiter together with a normally located multinodular goiter is a rare entity, and this is the first to be reported in North America.

Ectopic Thyroid Presenting as a Submandibular Mass

“…Ectopic thyroid is defined as thyroid tissue not anterolateral to the second, third and fourth tracheal rings, in the midline [1,3,5,9]. It is the most common form of thyroid dysgenesis, accounting for 48-61% of all cases [6].…”

“…It is the most common form of thyroid dysgenesis, accounting for 48-61% of all cases [6]. Although its incidence is not known, studies on necropsy suggest that 7-10% of the adults can be asymptomatic carriers of thyroid tissue in the thyroglossal duct path [5,6,9].…”

“…The first case of ectopic thyroid was published in 1869 by Hickman, who described a lingual thyroid in a newlyborn baby that underwent suffocation 16 h after birth as a consequence of a tissue mass that caused upper airway obstruction [3,9].…”

“…Ectopic thyroid tissue usually occurs in the midline, from the foramen caecum to the mediastinum [1,5,7,9] as a result of abnormal median migration and is rarely present lateral [1,10]. A lingual location is most common, accounting for 90% of the reported cases [1,3,5,6,[8][9][10].…”

“…In some rare cases, the lack of merging of the lateral cell clusters with the median can cause a lateral ectopic thyroid gland [1,3]; when this occurs thyroid tissue is located in the submandibular region [1,3,4,[7][8][9][10].…”