Can you guess why this patient was imaged after routine examination by a pediatrician? The sagittal T1 image demonstrates an isointense to slightly hyperintense round mass at the base of the tongue, which was visualized on physical exam. The appearance and location is consistent with ectopic lingual thyroid tissue. The findings can also be easily made on CT and nuclear medicine I-123 scans. The thyroid gland originates embryologically at the base of the tongue and descends to its normal cervical position during the first 8 weeks of gestation. The foramen cecum is the remaining anatomic landmark that corresponds to the embryologic origin of the thyroid gland. Arrest of normal migration results in deposition of thyroid tissue anywhere along its path of descent. Most cases result in complete arrest with no cervical thyroid tissue identified. The presence or absence of cervical thyroid tissue on imaging studies is pertinent, as it helps determine if and how much thyroid replacement therapy may be required if symptoms require surgical resection.Back To Top
Rivard D. At the Viewbox: Lingual Thyroid. J Am Osteopath Coll Radiol. 2012;1(3):33.