Thyroid often carcinomas, although cancer can occur in any tissue that the thyroid consists of, including cancer of C-cells and lymphomas. Cancers from other sites also rarely lodge in the thyroid. Radiation of the head and neck presents a risk factor for thyroid cancer, and cancer is more common in women than men, occurring at a rate of about 2:1. In most cases, thyroid cancer presents as a painless mass in the neck. It is very unusual for thyroid cancers to present with other symptoms, although in some cases cancer may cause hyperthyroidism. Most malignant thyroid cancers are papillary, followed by
Thyroid is the production of the iodine-containing thyroid hormones, triiodothyronine (T) and thyroxine (T) and the peptide hormone calcitonin. T is so named because it contains three atoms of iodine per molecule and T contains four atoms of iodine per molecule. The thyroid hormones have a wide range of effects on the human body. These include: After secretion, only a very small proportion of the thyroid hormones travel freely in the blood. Most are bound to thyroxine-binding globulin (about 70%), transthyretin (10%), and albumin (15%). Only the 0.03% of T and 0.3% of T traveling freely have hormonal activity. In addition,