The term arenal tumor can refer to one of several benign and malignant neoplasms of the adrenal gland, several of which are notable for their tendency to overproduce endocrine hormones. Adrenal cancer specifically refers to malignant adrenal tumors, which include neuroblastoma, adrenocortical carcinoma, and a minority of adrenal pheochromocytomas. Most adrenal pheochromocytomas and all adrenocortical adenomas are benign tumors, which do not metastasize or invade nearby tissues, but which may still cause significant health problems by giving rise to hormonal imbalances.