Causes and Treatment of Pheochromocytoma

What is this condition?

A pheochromocytoma is a tumor of the adrenal medulla, the central core of the adrenal gland that secretes two hormones: epinephrine and norepinephrine. These hormones are called catecholamines. This tumor causes the adrenal medulla to produce an excess amount of catecholamines, resulting in high blood pressure, increased metabolism, and increased blood sugar.

The disorder affects all races and both sexes, occurring primarily between ages 30 and 40. It's potentially fatal, but the prognosis is generally good with treatment. However, pheochromocytoma-induced kidney damage is irreversible.

What causes it?

A pheochromocytoma may result from an inherited genetic trait. According to some estimates, about 0.5% of newly diagnosed people with high blood pressure have pheochromocytoma. Although this tumor is usually benign, it may be malignant in as many as 10% of these people.

What are its symptoms?

The most important sign of pheochromocytoma is persistent or recurrent high blood pressure. Common symptoms include palpitations, fast pulse, headache, sweating, pallor, warmth or flushing, numbness and tingling, tremor, nervousness, feelings of impending doom, abdominal pain, rapid breathing, nausea, and vomiting.

Other common effects of this disorder are postural hypotension (abnormally low blood pressure when a person stands up) and a paradoxical response to drugs used to treat high blood pressure (the drugs cause blood pressure to rise instead of decrease). The person may also develop high blood sugar and hypermetabolism. People with hypermetabolism may show marked weight loss, although some people with pheochromocytoma are obese.

Symptoms may occur as seldom as once every 2 months or as often as 25 times a day. They may occur spontaneously or may follow certain precipitating events, such as changes in posture, exercise, laughing, smoking, induction of anesthesia, urination, a change in environmental or body temperature, or pregnancy. A person who has periodic attacks may have no symptoms during a latent phase.

How is it diagnosed?

The doctor makes a diagnosis based on the patient's health history, a physical exam, and lab tests. He or she will suspect pheochromocytoma if a person has a history of acute episodes of high blood pressure, headache, sweating, and palpitations, especially if the person also has high blood sugar, sugar in the urine, or hypermetabolism.

In rare cases, the doctor may be able to feel the tumor during inspection. Diagnosis is confirmed by a test of urine collected over a 24-hour period showing elevated levels of catecholamines.

Angiography (X-ray studies of blood vessels using contrast dye) demonstrates an adrenal medullary tumor (but the procedure may precipitate a hypertensive crisis). Various kidney function studies, adrenal venography, or computed tomography scan (commonly called a CAT scan) help to localize the tumor.

How is it treated?

Surgical removal of the tumor is the treatment of choice. To decrease blood pressure, drugs such as alpha-adrenergic blockers or Demser are given 1 to 2 weeks before surgery. A beta-adrenergic blocker such as Inderal may also be used. After surgery, intravenous fluids, plasma volume expanders, vasopressors and, possibly, transfusions may be required to treat low blood pressure. Persistent high blood pressure can occur immediately after surgery.

If surgery isn't feasible, alpha- and beta-adrenergic blockers­such as Dibenzyline and Inderal, respectively - are beneficial in controlling catecholamine effects and preventing attacks.

Management of an acute attack or hypertensive crisis requires intravenous Regitine or Nitropress to normalize blood pressure.

What can a person with pheochromocytoma do?

• Report headaches, palpitations, nervousness, or other symptoms of an acute attack.

• If the doctor suspects your disease was inherited, other members of your family should be evaluated for it.