One case of the Lingual Thyroid

설갑상선 1례

Lingual thyroid is the term applied to a mass of ectopic thyroid tissue located on the base of the tongue in the midline. It may be found anywhere between the circumvallate papillae and the epiglottis. It is believed to be caused by developmental anomalies involving the descent of the embryologic gland anlage from its position posterior to the tuberculum impar to its normal pretracheal location between week 3 and week 7 of embryologic development. Differential diagnosis of the lingual thyroid would include lingual tonsillar hypertrophy, vallecular cyst, thyroglossal duct cyst, epidermal cyst, lymphoma. Lingual thyroid is found in approximately 1 in 100,000 people, and affected individuals have no other thyroid tissue in 70% to 100% of cases. Recently, we have experienced a case of lingual thyroid with mild dysphagia in a 48-year-old male. Now we report the case with literature review.