Definition

Pheochromocytoma is a tumor made up of special adrenal gland cells known as the chromaffin cells which secrete epinephrine, norepinephrine, and dopamine. These hormones are active in the regulation of heart [3] rate and blood pressure. Pheochromocytoma cells periodically secrete excessive amounts of the hormones epinephrine and norepinephrine, resulting in periods of very high blood pressure [4] , rapid heart [3] beats or palpitations, excess sweating, and severe headaches.

Most pheochromocytoma are benign (noncancerous) and about 10% are malignant (cancerous). Most pheochromocytoma grow on the adrenal glands, which are themselves perched on top of the kidneys [5]. About 10%-20% of all pheochromocytoma occur elsewhere in the body.

Causes

The cause of pheochromocytoma is not yet known. Scientists suspect a genetic link.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.

Factors associated with pheochromocytoma include:

• A family history of pheochromocytoma, tumors in other glands of the body, or other hormonal disorders
• Genetic diseases including:
  • Von Hippel-Lindau disease [6]
  • Multiple endocrine neoplasia, type 2
  • Neurofibromatosis type 1 [7]
  • Paraganglioma syndromes

Symptoms

Up to 50% of patients have no symptoms. Pheochromocytoma is found by a CT scan [8] or MRI scan [9] during the investigation of some other unrelated illness.

Symptoms may occur many times during the day or as infrequently as once every few months. Symptoms may be brought on by pressure on the tumor (as might occur accidentally during a massage), medications (such as certain anesthetics and beta-blockers), or intense emotion. Symptoms can include:

• Severe headaches
• Excessive sweating
• Fast heart [3] rate ( tachycardia [10] )
• Sensation of a panic attack
• Vision changes (blurred vision)
• Nausea, vomiting, constipation
• Pounding heart [3] beat (palpitations)
• Chest pain [11]
• Involuntary trembling (tremor)
• Pain in the lower chest or upper abdomen
• Warmth, flushing
• Increased appetite
• Weight loss
• Insomnia [12]
• High blood pressure (either sporadic or constant)
• Tingling, burning, or numbness in the legs and feet
• Shortness of breath
• Muscle weakness
• Anxiety [13]
• Intolerant to high temperature

Diagnosis

Your doctor will take a medical [14] history and perform a physical exam. Diagnosis of pheochromocytoma may include the following tests:

• 24-hour urine testing—to measure amounts of catecholamines (a group of hormones made by the adrenal glands near the kidneys), including epinephrine and norepinephrine and their byproducts (metanephrines)
• Blood testing—to measure catecholamines and metanephrines
• Clonidine suppression test—a dose of the drug clonidine is given, and blood levels of norepinephrine are tested
• CT scan—a type of x-ray that uses a computer to make pictures of structures inside the body
  • The CT scan can be used to diagnose the presence of the tumor.
• Ultrasound [8] —a noninvasive test using sound waves, which may be used to help detect adrenal tumors
• MRI scan—a test that uses magnetic waves to produce cross-sectional or three-dimensional images of the body’s tissues
• MIBG scintiscan (or adrenal medullary imaging)—an imaging test for diagnosing adrenal tumors, in which tiny amounts of radioactive materials are injected into the body

Treatment

If pheochromocytoma is benign (not cancerous), then the tumor is surgically removed. Laparoscopic [15] adrenalectomy is the surgical removal of the adrenal glands. It involves making three or four small incisions in the abdomen and inserting a special camera through the incisions so that the surgeon can see the tumor area.

Sometimes, the adrenal glands are removed as a part of this process. Prior to surgical removal, the high blood pressure will need to be brought under control, using first the medication phenoxybenzamine, followed by beta-blocking antihypertensive agents.

If pheochromocytoma is cancerous and have spread outside of the adrenal glands, chemotherapy [16] involving the use of docarbazine, vincristine, and cyclophosphamide could be tried.

Prevention

Since little is known about the causes of pheochromocytoma, prevention methods are not available.