The adrenal glands are two glands that sit on top of the kidneys. Each gland is divided into two different sections: the cortex and the medulla. Both portions of the adrenal glands secrete different kinds of hormones. Adrenal adenomas are benign tumors of the adrenal gland and come in both functional and non-functional varieties.
Nonfunctioning
Nonfunctioning adrenal adenomas are tumors of the adrenal gland that do not produce hormones, the Merck Manual explains. Because these tumors do not produce any hormones, they often cause no symptoms. In many cases, these tumors are only discovered as an incidental finding on an imaging scan, such as an MRI or a CT scan. In rare cases, these adenomas can begin to bleed, either due to a blood clot elsewhere in the body breaking off and causing the mass to rupture, or due to poor blood clotting. Unless these tumors are very large or are causing dysfunction of the adrenal glands, they do not need to be removed. Adrenal adenomas that are larger than 4 cm in diameter are typically removed surgically.
Functional Cortex Adenomas
The cortex of the adrenal glands produces three different hormones, the Dartmouth-Hitchcock Medical Center notes. Aldosterone is a hormone that helps regulate the balance of sodium in the body and also has an effect on the body's ability to control the amount of water it retains. Cortisol, the second hormone, modulates the body's stress response. Finally, the adrenal cortex produces small amounts of androgens, which are hormones, such as testosterone, which promotes the secondary sexual characteristics of a male such as facial hair and a deepening voice. Functioning adenomas of the adrenal cortex can overproduce one or more of these hormones. Aldosterone-producing adenomas can lead to high blood pressure and low levels of potassium. Cortisol-producing tumors can result in diabetes, obesity and a series of symptoms known as Cushing's syndrome. Androgen-secreting tumors can cause boys to hit puberty prematurely, and can cause females to develop typically male characteristics.
Pheochromocytoma
Pheochromocytomas are functioning tumors of the adrenal medulla. These adenomas produce large amounts of adrenaline, the hormone product of the middle of the adrenal glands. Pheochromocytomas can result in extremely high blood pressure, a racing heart and headaches, Endocrine Web explains. These tumors can also cause patients to shake, feel unusually anxious, lose weight and become intolerant to heat. Patients, who have high blood pressure that is difficult to treat or requires more than four medications, may have this variety of adenoma. These tumors must be treated surgically as the excess adrenaline can cause serious health problems.
