The adrenal gland is a paired organ that sits like a cap on the kidney. It is an essential hormonal center of the body, and the body particularly needs the adrenal gland to be able to deal with stress and illness. It consists of a cortex that is made up of three zones and, that in addition to other steroid hormones, produces sex hormones and cortisone. Stress hormones are synthesized in the adrenal medulla (in the center of the organ). A small population of cells from each of these finely tuned areas may multiply (uncontrollably) and form a benign or malignant tumor. The clinical picture is varied and is dominated by the type of hormone produces in excess.