A thyroid nodule is defined as a small lump of tissue (either solid or cystic - filled with fluid), usually more than one quarter of an inch in diameter that may protrude from the neck's surface or may form in the thyroid gland itself. The nodule can be either benign (non-cancerous) or malignant (cancerous).

Even though the incidence of thyroid nodules (4 to 7 percent of the population) and thyroid cancer (1 percent of the population) is rare, there are certain risk factors that could make a...