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 in young-adult to mid-adult life. 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.
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 - blood
Treatment
The definitive treatment is removal of the tumor by surgery. Continuous monitoring of all vital signs is necessary in the postoperative period in an intensive care unit. Stabilization of the person's vital signs with medication prior to surgery is important and may require hospitalization. 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 noncancerous tumors that are removed with surgery, the 5-year survival rate is 95%, with recurrence in less than 10% of patients. Hormone secretion of norepinephrine and epinephrine returns to normal after surgery. For patients who have malignant tumors, the 5-year survival rate after surgery is less than 50%.
Complications
High blood pressure may not be cured in one-fourth of the people 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.