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 without suspicious features should not undergo further evaluation. Nevertheless, further workup might be necessary for such individuals if it is clinically warranted, or specifically requested by the referring physician or the patient. In patients with ITNs, it is important to inquire about pertinent historical factors predicting malignancy. These factors include history of childhood or adolescent head and neck or total body radiation exposure, and familial thyroid carcinoma or thyroid cancer syndrome. Syndromes associated with thyroid cancer include multiple endocrine neoplasia 2, familial adenomatous polyposis, Carney complex, Cowden’s disease, and Werner syndrome/progeria. If a patient has a first-degree relative with such