Hashimoto's thyroiditis: an accidental discovery of a lingual thyroid in a 7-year-old child.

An ectopic thyroid located at the base of the tongue is a rare entity, resulting from early developmental defects of thyroid gland embryogenesis during its descent from the foramen caecum to its normal eutopic pretracheal site. This condition is the main cause of congenital primary hypothyroidism, even though signs and symptoms of thyroid dysfunction may also appear later in childhood. Lingual thyroid may sometimes present with symptoms of respiratory obstruction or feeding difficulties.