The adrenal glands are located on top of the kidneys. These glands produce a variety of hormones that can affect tissues throughout the body. Adrenal tumors can be cancerous or benign; both kinds of adrenal tumors can secrete hormones, disrupting the body's hormonal balance and leading to serious health conditions.
Hormones
The adrenal glands are a part of the endocrine system, which means that they produce many different hormones for the body, the University of Maryland Medical Center explains. The outside portion of the adrenal glands, which is also known as the adrenal cortex, produces three different kinds of hormones: corticosteroids, which affect the body's response to stress; aldosterone, which regulates salt and water balance; and androgens, which help secondary sexual characteristics develop. The inside of the adrenal glands is also known as a the adrenal medulla. This part of the gland produces catecholamines, such as adrenaline. The function of these hormones is to stimulate the body's fight-or-flight response.
Control
The production of hormones by the adrenal glands is controlled by the pituitary gland. The pituitary gland releases a hormone called corticotropin, which stimulates the release of hormones by the adrenal cortex. The release of corticotropin, on the other hand, is controlled by the amount of another hormone, called corticotropin-releasing hormone. This latter hormone is made by the hypothalamus, which is located in the brain.
Adenomas
Adrenal adenomas, the American Cancer Society explains, are non-cancerous tumors of the adrenal cortex. They usually occur in only one of the adrenal glands and are often less than 2 inches in diameter. In general, no symptoms occur with these tumors; they are sometimes discovered during a routine MRI or other imaging scan. In some cases these tumors can produce large amounts of adrenal hormones, such as aldosterone, which can lead to the development of serious health problems, such as high blood pressure.
Adrenal Carcinomas
Adrenal carcinomas are cancerous tumors that occur in the cortex. These tumors often grow much larger than adenomas and are, on average, about 5 inches in diameter. Sometimes these tumors secrete hormones. Carcinomas that secrete too much cortisol lead to a condition known as Cushing's syndrome, which is marked by truncal obesity and the redistribution of fat in the body. Other kinds of carcinomas can secrete androgens, such as testosterone, which can lead to early puberty and the development of facial hair in females.
Tumors of the Medulla
There are two different kinds of tumors that can affect the medulla of the adrenal glands, the American Society of Clinical Oncology notes. Neuroblastomas are a form of cancer that often begins in the adrenal medulla and affects children early in life. This type of cancer is formed from neuroblasts, which are immature cells that can either become nerve cells or adrenal medulla cells. The other kind of medulla tumor is known as a pheochromocytoma. This tumor secretes large amounts of adrenaline.
