Adrenal gland tumors are usually benign, not cancerous, according to MedlinePlus. Generally, they do not cause symptoms and may not require treatment. Pheochromocytoma is one type of adrenal gland tumor that is rare and is usually benign.
Each kidney has an adrenal gland on top of it that produces essential hormones such as sex hormones and cortisol for stress response, as MedlinePlus states. A pheochromocytoma frequently causes the adrenal gland to make too many hormones, which can lead to high blood pressure. The tumor can cause symptoms such as pounding of the heart, sweating, headaches, shaking and paleness.
Lab and imaging tests are used to diagnose pheochromocytomas and the tumors are commonly treated with surgery. Other treatments can be used, such as radiation therapy and chemotherapy, according to MedlinePlus.