Pheochromocytoma

Definition

Pheochromocytoma is a tumor of the core of the adrenal glands that secretes excessive amounts of the hormones epinephrine and norepinephrine, resulting in high blood pressure.

Description

Pheochromocytoma is a rare disease in which a tumor causes the adrenal medulla to overproduce epinephrine and norepinephrine hormones. This overproduction of hormones causes high blood pressure and increased metabolism and may elevate blood sugar. Pheochromocytoma occurs primarily in adults 30-40 years of age. It can be life threatening if untreated, and can cause stroke, or damage to the kidneys, brain, or heart.

Pheochromocytoma is usually benign and does not spread to other organs. It may be associated with other endocrine gland tumors.

Causes & symptoms

The cause of pheochromocytoma is not known, but scientists suspect a genetic link. Persistent or recurrent high blood pressure is the most important sign of pheochromocytoma. Other signs and symptoms include:

• Excessive sweating
• Palpitations
• Fast pulse
• Headache
• Pallor
• Weight loss
• Constipation
• Warmth or flushing
• Numbness and tingling
• Tremor
• Nervousness
• Feelings of doom
• Rapid breathing
• Abdominal pain, nausea, and vomiting.

These symptoms may occur as often as 25 times a day or as infrequently as once every few months.

Diagnosis

Pheochromocytoma can be diagnosed based on a number of factors, including a physical examination; blood and urine lab tests, which measure urinary catecholamines and epinephrine and norepinephrine in blood and urine; and imaging, including computed tomography scan (CT scan) and magnetic resonance imaging (MRI). A CT scan uses ultrafast electron beams to produce three-dimensional views of organs. It is performed at a hospital or clinic and takes only minutes. An MRI is a computerized scanning method that uses radio waves and a magnet to scan body parts. An MRI is usually performed at a hospital and takes about 30 minutes. There is also a radionucleide scan that can help localized pheochrocytones that are not in the usual gland location. This is metarodobenzylguanidine (MIBG) with I₁₂₃ (iodine isotope).

Treatment

Laparoscopic surgical removal of the tumor is the treatment of choice for pheochromocytoma. Before surgery, medications such as alpha-adrenergic blockers are given to block the effect of the hormones and normalize blood pressure. Laparoscopic laparotomy is a minimally invasive outpatient procedure performed under general or local anesthesia. A small incision is made in the abdomen. The laparoscope is inserted into the incision and the tumor is removed. Laparoscopic laparotomy enables the patient to return to normal activities with two weeks. Traditional laparotomy is performed in a hospital under spinal or general anesthesia and requires 5-7 days in the hospital and a four-week recovery period. The surgical mortality rate is less than 3%. A beta-blocker, such as Inderal, may also be used. For patients for whom surgery is not appropriate, drug therapy with alpha- and beta-adrenergic blockers can often control the effects of excess hormone production and prevent attacks. During an acute attack or a hypertensive crisis, intravenous Regitine or Nipride are administered to bring the blood pressure down to normal.

Prognosis

Untreated pheochromocytoma can be fatal. When the tumor is surgically removed before irreparable damage has been done to the cardiovascular system, pheochromocytoma is cured.

Prevention

Pheochromocytoma cannot be prevented.

Key Terms

Adrenal medulla

The central core of the adrenal gland which is located near or upon the kidneys.

Laparoscopic

Relating to the laparoscope, an instrument used to examine body cavities during certain types of surgery.

Tumor

A swelling, in this case in the adrenal glands.

Further Reading

For Your Information

Books

• Tierney, Lawrence M., Stephen J. McPhee, and Maxine A Papadakis. eds. "Diseases of the Adrenal Medulla." In Current Medical Diagnosis & Treatment, Stamford, CT: Appleton & Lange, 1997.

  Periodicals

• Dluhy, Robert G. "Uncommon Forms of Secondary Hypertension in Older Patients." American Journal of Hypertension, 11 (1998): 52S-56S.
• McGrath, Patric C., David A Sloan, Richard W. Schwartz, and Daniel E. Kenady. "Advances in the Diagnosis and Therapy of Adrenal Tumors." Current Opinions in Oncology, 19 (1998): 52-57.
• Takami, Hiroshi, and Hiroshi Miyoshi. "Laparoscopic Adrenalectomy in Asymptomatic Pheochromocytoma." American Surgeon, 63 (September 1997): 820.

  Other

• Thriveonline.com"Pheochromocytoma," "Laparotomy," and "Adrenal Gland Removal." http://www.thriveonline.com/health/Library/ (13 May 1998).

Gale Encyclopedia of Medicine. Gale Research, 1999.