Adrenal Disorders Pheochromocytoma

Normally, the adrenal medulla, the central portion of the adrenal gland, makes adrenaline in response to stress—the "fight or flight response." Pheochromocytomas are rare tumors arising from the center of the adrenal gland, also called the medulla, which overproduce adrenaline. They are often called the "10 percent tumor" because 10 percent of pheochromocytomas are:

• Malignant—behave like cancer and can spread
• Bilateral—are found in both adrenal glands
• Pediatric—are found in children
• Familial—run in families
• Extra-Adrenal—are found outside the adrenal glands

Outside the adrenal glands, pheochromocytomas can be found anywhere along the sympathetic nervous chain. The most common extra-adrenal site is the organ of Zuckerkandl, located at the aortic bifurcation.

Diagnosis

Patients with pheochromocytomas may have symptoms related to increased adrenaline. They may intermittently complain of episodes of sweating, headaches, palpitations, and anxiety. They may also have nausea, weight loss, and heat intolerance. High blood pressure that begins before the age of 35 or after the age of 60, is difficult to control, requires more than four medications, or occurs with the above symptoms, should raise the suspicion of pheochromocytoma.

The diagnosis is made by evaluating the urine for catecholamines (adrenaline and noradrenaline) and metanephrines (metabolites or breakdown products). While the blood level of catecholamines is also evaluated, this test has a higher false positive rate (i.e. incorrectly positive results) then the urine analysis. Patients diagnosed with pheochromocytoma undergo special scanning (i.e., CT, MRI, or MIBG) to localize the tumor.

Treatment

The safe management of pheochromocytomas begins by using medications to block the body's response to adrenaline. These medications, known as alpha and beta blockers, relax the blood vessels-reducing blood pressure, and allow the body to rehydrate in preparation for surgery. It is very important for the patient to drink plenty of fluids and stay well hydrated during this period of preparation since it makes it easier to control blood pressure during and after the operation. Once the patient is adequately prepared, it is safe to proceed with surgery. Most tumors can be removed laparoscopically, through several very small incisions.