Thyroid dysgenesis thyroid gland may be located anywhere along the path of the descent of the thyroid during its embryological development, although it is most commonly located at the base of the tongue, just posterior to the foramen cecum of the tongue. In this location, an aberrant or ectopic thyroid gland is known as a "lingual thyroid". If the thyroid fails to descend to even higher degree, then the resulting final resting point of the thyroid gland may be high in the neck, such as just below the hyoid bone. Parts of ectopic thyroid tissue ("accessory thyroid tissue") can also occur, and
Computed tomography of the thyroid 70 % of cases, the ectopic thyroid is the only functional thyroid tissue present in the body (Fig. 18). Ectopic thyroid tissue lateral to the orthotopic midline location is rare. The exact anatomical definition of this rare entity is debated in the literature. To avoid confusion, some authors define a lateral neck ectopic thyroid as any thyroid tissue superficial to the strap muscles with no midline continuity. The majority of lateral thyroid ectopia cases have been reported as lesions closely related to the strap muscles. There are few reported cases of ectopic lateral thyroid tissue in the submandibular region, jugulodigastric