What is cancer, and what are the types of thyroid cancer?
Cancer is a group of many related diseases. All cancers begin in cells, the body’s basic unit of life. Cells make up tissues, and tissues make up the organs of the body. Normally, cells grow and divide to form new cells as the body needs them. When cells grow old and die, new cells take their place. Sometimes this orderly process goes wrong. New cells form when the body does not need them, and old cells do not die when they should. These extra cells can form a mass of tissue called a growth or tumor. Growths on the thyroid are usually called nodules. Thyroid nodules can be benign or malignant: • Benign nodules are not cancer. Cells from benign nodules do not spread to other parts of the body. They are usually not a threat to life. Most thyroid nodules (more than 90 percent) are benign. • Malignant nodules are cancer. They are generally more serious and may sometimes be life threatening. Cancer cells can invade and damage nearby tissues and organs. Also, cancer cells can break away from
