An adrenocortical adenoma or adrenal adenoma is commonly described as a benign neoplasm emerging from the cells that comprise the adrenal cortex. Like most adenomas, the adrenocortical adenoma is considered a benign tumor since the majority of them are non-functioning and asymptomatic.

Benign adrenal tumors that grow in the cortex are called adrenal adenomas. Those that grow in the medulla are called pheochromocytomas (fee-o-kroe-moe-sy-TOE-muhs). Most benign adrenal tumors cause no symptoms and don't need treatment.