The adrenal glands are part of the endocrine system, which releases hormones into the blood system. Hormones are important in many body processes, including metabolism, sexual development and puberty, and stress.
There are two adrenal glands, one on the top of each kidney. They are shaped like triangles, and each is about ½ inch high and 3 inches long.
Each gland has two parts:
Medulla: The inner part of the adrenal gland. It makes hormones called catecholamines, which include adrenaline and noradrenaline. These “stress hormones” increase alertness, strength and speed in an emergency. They also affect heart rate, blood pressure and sweating.
Cortex: The outer part of the adrenal gland. It makes:
- Mineralocorticoid hormones that affect blood pressure, and salt and acid-base potassium balance
- Glucocorticoids, such as cortisol, that regulate stress and metabolism, and play a part in the use of fats
- Hormones that play a part in the use of fats, carbohydrates and protein
Adrenal gland tumor can be malignant (cancer) or benign (not cancer). Even benign adrenal gland tumor can be dangerous or cause uncomfortable symptoms. There are several different types of adrenal gland tumors and related conditions.
Adenomas are a type of non-cancerous tumor.
This type of malignant tumor originates in the cortex of the adrenal gland. It is a rare cancer, affecting only about 300 to 500 people each year in the United States. There are two main types of adrenocortical cancer:
Functioning tumors are the most common type and account for about 70% of adrenal cancers. These tumors make hormones, such as cortisol, androgens or aldosterone.
Non-functioning tumors do not produce hormones.
Malignant adrenal pheochromocytomas begin in the medulla. They are extremely rare, and only about 800 cases are diagnosed each year in the United States.
Malignant paragangliomas, which may begin inside or outside the adrenal gland.
Cushing's syndrome is a non-cancerous condition in which the adrenal gland produces an excess of cortisol, a hormone that plays a part in regulating blood pressure, heart function and the body’s reaction to stress. Cushing’s syndrome is rare. About two to four new cases per 1 million people are diagnosed in this country each year.
Overproduction of cortisol may be caused by:
- A benign tumor on the adrenal gland called an adenoma
- An abnormality of the pituitary gland, usually a tumor (also called Cushing’s disease)
- Long-term use of corticosteroid medications (such as prednisone)
- Benign or malignant tumors in other areas of the body that produce adrenocorticotropic hormone (ACTH) (ectopic ACTH syndrome)
Hyperaldosteronism is caused by a small tumor in the adrenal gland that makes too much aldosterone or an enlargement (hyperplasia) of the adrenal glands. A high level of aldosterone plays a part in the body’s salt and potassium balance, and may cause high blood pressure. In fact, it is believed that 10% of people with high blood pressure have hyperaldosteronism.
Adrenal gland tumor risk factors
Certain inherited disorders can increase your risk of having an adrenal disease. These include:
- Li-Fraumeni syndrome
- Multiple Endocrine Neoplasia type 2 (MEN2)
- Von Hippel-Lindau disease (VHL)
- Neurofibromatosis type 1, also known as von Recklinghausen’s disease
- Paraganglioma syndrome
- Beckwith-Wiedemann syndrome
Not everyone with these syndromes develops an adrenal tumor. However, if you or anyone in your family has one of these syndromes, your doctor may recommend genetic testing. MD Anderson offers the most advanced genetic testing to let you know your risk of developing adrenal gland tumors.