When the medial anlage of the thyroid gland fails to descend into the neck from its point of origin in the oropharynx, a lingual (accessory) thyroid results. In 1936 Montgomery1 proposed standard criteria for the diagnosis of this anomaly: (a) location of the aberrant tissue at the base of the tongue between the circumvallate papillae and the epiglottis, (b) microscopic demonstration of thyroid tissue, and/or (c) development of hypothyroidism following removal of the lesion. Subsequently, recognition of the lingual thyroid has been greatly facilitated by radioiodine tracer techniques, so that, in practice, concentration of I131 by such a lesion is now considered adequate evidence for the diagnosis.
While diagnosis has been greatly simplified, the problem of treatment has stimulated some debate. Several therapeutic measures have been employed, including suppression with inorganic iodine, ablation with radioiodine, subtotal resection, and total excision. Medical therapy with inorganic iodine has been employed
SWAN H, JENKINS D, MACGREGOR C. Autotransplantation of the Lingual Thyroid. AMA Arch Surg. 1958;76(3):458-464. doi:10.1001/archsurg.1958.01280210128026