Cancer does not always present symptoms, but is usually found during screening processes. People at high risk such as those who are exposed to radiation through work or other situations should inform their doctor. Also, individuals who have goiter or a family history of the cancer should report this during the screening process. In turn, doctors who think that a person may have cancer will look for a lump in the neck, difficulty when breathing or swallowing, and/or hoarseness as well as change of the voice. The location of the thyroid is in the anterior part of the neck. The lobes of the thyroid are position lateral to the upper portion of the trachea. The thyroid is inferior to the larynx with the isthmus extending across the anterior aspect of the trachea. The gland is composed of two lobes connected by a narrow band, the isthmus, of thyroid tissue. The thyroid is surrounded by a thin fibrous capsule that is attached by dense connective tissue to the cricoids cartilage and superior tracheal ring. A normal gland weighs approximately 10 – 30 grams [gm] which make it one of largest endocrine gland in the body. Thyroid Furthermore, the thyroid contains small sphere whose walls are composed of single layer cuboidal epithelial cells called follicles. Each center of the follicle is filled with protein
called thyroglobulin. The thyroglobulin helps the follicles store large amounts of the thyroid hormones. While, scattered para-follicular cells are found between the follicules among the cells that make up the walls of the follicle. The para-follicular cells secrete calcitonin. Calcitonin plays a major role in reducing the concentration of the calcium in the body when the levels are elevated. In addition, the thyroid also controls how quickly the body uses energy, makes proteins, and controls how sensitive the body is to other hormones present. Normal Thyroid Cells Two hormones produced by the thyroid are triiodothyrine (T3) and tetraiodothyronine also called thyroxine (T4). These hormones
regulate the rate of metabolism; affect the growth and rate of functions of many other systems of the body. They are synthesized by iodine and tyrosine. These hormones pass through the circulatory system with the plasma proteins. Additionally, thyroid hormones are involved in the normal growth and maturation of organs. For example, the bones, the brain, hair, teeth, connective tissue and nervous tissue require the hormone for growth and development. Typically, patients who have had their thyroids removed or suffer from hyper/hypo-thyroidism are place on synthroid as a life-long replacement therapy drug.