Radiation therapy was commonly used in the 1950s to treat enlarged thymus glands, adenoids and tonsils, and skin disorders. A higher incidence of thyroid cancer is present in people who received radiation therapy as children. Other risk factors are a family history of thyroid cancer and chronic goiter . The overall incidence is 1 out of 1,000 people. There are several different types of thyroid cancer.
Papillary carcinoma is the most common and usually affects women of child-bearing age.
It metastasizes slowly and is the least malignant type of thyroid cancer. Medullary carcinoma can produce symptoms similar to Cushing's syndrome and tends to occur in families. It metastasizes quickly and invades nearby structures such as the trachea, causing compression and breathing difficulties . An examination of the thyroid reveals single or multiple nodules . Treatment varies depending on the type of tumor.