Pheochromocytoma

Definition

Pheochromocytoma is a tumor of the adrenal gland that causes excess release of epinephrine and norepinephrine, hormones that regulate heart rate and blood pressure.

Causes, incidence, and risk factors

Pheochromocytoma may occur as a single tumor or as multiple growths. It usually develops in the medulla (center or core) of one or both adrenal glands. Sometimes this kind of tumor occurs outside the adrenal gland, usually somewhere else in the abdomen. Less than 10% of pheochromocytomas are malignant (cancerous), with the potential to spread to other parts of the body.

The tumors may occur at any age, but they are most common from early to mid-adulthood. A common clinical feature is a paroxysm (an attack of symptoms listed below) that may be frequent but sporadic (occurring at unpredictable intervals). The paroxysms may increase in frequency, duration and severity as the tumor grows.

Symptoms

• Severe headache
• Palpitations
• Rapid heart rate
• Sweating
• Flushing
• Chest pain
• Abdominal pain
• Nervousness
• Irritability
• Increased appetite
• Loss of weight

• Sleeping difficulty
• Hand tremor
• High blood pressure

Signs and tests

Vital signs (temperature, pulse, rate of breathing, blood pressure) reveal high blood pressure (hypertension) that may be sustained or episodic, rapid heart rate, and elevated temperature.

Tests include:

• An adrenal biopsy that shows pheochromocytoma
• A MIBG scintiscan that shows tumor
• An MRI of abdomen that shows adrenal mass
• An abdominal CT scan that shows mass.
• Elevated urine metanephrine
• Elevated urine catecholamines
• Abnormal results of a glucose test
• Abnormal levels of catecholamines in the blood

Treatment

The definitive treatment is removal of the tumor by surgery. Stabilization of the person's vital signs with medication prior to surgery is important, and may require hospitalization. After surgery, it is necessary to continually monitor all vital signs in an intensive care unit. In the case of an inoperable tumor, management with medication is necessary. Radiation therapy or chemotherapy have not been effective in curing this kind of tumor.

Expectations (prognosis)

For patients who have non-cancerous tumors that are removed with surgery, 95% of these patients are still alive after 5 years. The tumors come back in less than 10% of these patients. Hormone secretion of norepinephrine and epinephrine returns to normal after surgery.

For patients who have cancerous tumors that are removed with surgery, less than 50% of patients are alive after 5 years.

Complications

High blood pressure may not be cured in 25% of patients after surgery, yet control is usually achieved in these people with standard treatments for hypertension. Recurrence of tumor may occur in 10% of the cases.

Calling your health care provider

Call your health care provider if you have symptoms of pheochromocytoma or if you have had a pheochromocytoma in the past and symptoms recur.

Illustrations

Endocrine glands

Adrenal metastases, CT scan

Adrenal Tumor - CT

Adrenal gland hormone secretion

Page Content:

Chromaffin tumors