The adrenal glands, located atop the kidneys, normally produce several types of hormones. Tumors of these glands may or may not secrete hormones. It is not known what causes these tumors or why some secrete hormones and others do not. Some of the tumors are benign and confined to the adrenal gland, and others are malignant (cancerous), and can spread to other parts of the body. This study will investigate how adrenal gland tumors develop, why some secrete steroid hormones and others do not, and why some are benign and others malignant.