Thyroid vertebrates. In fish, it is usually located below the gills and is not always divided into distinct lobes. However, in some teleosts, patches of thyroid tissue are found elsewhere in the body, associated with the kidneys, spleen, heart, or eyes. In tetrapods, the thyroid is always found somewhere in the neck region. In most tetrapod species, there are two paired thyroid glands – that is, the right and left lobes are not joined together. However, there is only ever a single thyroid gland in most mammals, and the shape found in humans is common to many other species. In larval
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