Case of thyroid hemiagenesis and ectopic lingual thyroid presenting as goitre.

Objective: We report an extremely rare case of thyroid hemiagenesis with ectopic lingual thyroid.

Methods: Case report and review of the world literature concerning thyroid hemiagenesis with ectopic lingual thyroid and heredity.

Results: Ectopic thyroid is an uncommon embryological aberration characterised by the presence of thyroid tissue in a site other than its usual, pretracheal location. The lingual thyroid is the most common manifestation of benign ectopic thyroid tissue, but is still a rare clinical entity. Thyroid hemiagenesis is also a very rare abnormality, in which one thyroid lobe fails to develop. We report a case of left thyroid hemiagenesis and goitre in the right lobe in a 26-year-old woman with an ectopic lingual thyroid.

Conclusions: To our knowledge, this is the first report in the world literature of thyroid hemiagenesis with ectopic lingual thyroid.