There are two adrenal glands, one on top of each kidney. The adrenal glands work interactively with the hypothalamus and pituitary gland in the brain. The adrenal gland is made of layers. Each layer makes different hormones. The outer layer (the adrenal cortex) makes cortisol, corticosterone, aldosterone, and androgen hormones. Cortisol helps regulate metabolism of fats, proteins and carbohydrates. Corticosterone, along with cortisol, supresses inflammatory responses and affects the immune system. Aldosterone regulates body levels of potassium and sodium as well as blood volume and blood pressure. Androgen hormones are converted to female and male hormones (estrogens and androgens) elsewhere in the body. Most of these hormones are produced in the ovaries and testes. The center of the gland (the adrenal medulla) makes epinephrine (adrenaline) and norepinephrine (noradrenaline). Epinephrine increases heart rate, blood pressure, and blood flow among other effects. Norepinephrine also increases blood pressure.
A pheochromocytoma is an adrenal gland tumor that secretes too much epinephrine (adrenaline) and norepinephrine (noradrenaline). These hormones are responsible for regulating heart rate and blood pressure, among other functions. Pheochromocytomas are tumors of the central portion of the adrenal gland (the adrenal medulla).
The most common sign of pheochromocytoma is high blood pressure. It can be constant or intermittently high. Sometimes, it produces extremely high blood pressure increases that can be life threatening. This is a very rare cause of high blood pressure, but it must be considered when medication is not enough to control high blood pressure. Other symptoms are less common, but can also be brought on by emotional stress or changes in posture. The following are the most common symptoms of pheochromocytoma. However, each individual may experience symptoms differently. Other symptoms may include:
High blood pressure
The symptoms of pheochromocytoma may resemble other medical conditions or problems. Always consult your doctor for a diagnosis.
In addition to a complete medical history and physical examination, diagnostic procedures for pheochromocytoma may include:
Blood and urine tests. These tests measure various hormone levels.
Computed tomography scan (also called a CT or CAT scan). A diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce detailed images of the body.
Magnetic resonance imaging (MRI). A diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.
Radioisotope scan. This procedure introduces radioactive substances into the body to create a functional image of the tumor. The radioisotope is taken up into tissues that make too much adrenaline. During the scan, this area will be highlighted. This is a whole-body scan and may be used to see if the disease is spreading, or if there is disease in other parts of the body.
Surgery to remove the tumor. The surgeon may remove one or both adrenal glands. The surgeon may either go through one open incision, or through several small incisions, using a laparoscope or camera inserted into the abdomen.
Medication. If a patient is too sick for surgery, the tumor can be managed with medication alone. This is done only in very rare cases, because this tumor is treated primarily with surgery.
The vast majority of these tumors are benign and will not come back after they are removed. There are cancerous forms of pheochromocytoma that can be diagnosed only when the tumor comes back or spreads to another location in the body. It is very hard to differentiate a benign tumor from a cancerous one simply by looking at it.