Pheochromocytoma

Other Names: Adrenal Gland Chromaffin Paraganglioma; Adrenal Gland Chromaffinoma; Adrenal Gland Paraganglioma; Intraadrenal Paraganglioma; Chromaffin Paraganglioma of the Adrenal Gland; Adrenal Gland Pheochromocytoma .

Pheochromocytomas are tumors of the adrenal glands. These glands are located right above the kidneys. Pheochromocytomas cause the adrenal glands to make too many stress hormones called epinephrines and norepinephrines. Pheochromocytomas may be found in one or both glands and may spread, or metastasize (pronounced meh-TAS-tuh-size), beyond the adrenal glands. Pheochromocytomas develop from the center of the adrenal gland, in an area called the adrenal medulla, which secretes catecholamines. Hormones that are normally produced by the adrenal medulla, catecholamines (pronounced kat-i-KOL-uh-meens), help to regulate heart rate, blood pressure, and the body's responses to stress. Pheochromocytomas release additional catecholamines, causing higher than normal amounts in the body.2 Changes in hormone levels produce some of the clinical signs and life-threatening symptoms of pheochromocytoma.

Cause

The cause of most pheochromocytomas is unknown. In some cases, there is a genetic cause. This type of tumor can occur in certain familial genetic syndromes, including multiple endocrine neoplasia, type 2 (MEN2), neurofibromatosis type 1, Von Hippel-Lindau disease, hereditary paraganglioma-pheochromocytoma syndrome, Carney triad, and Carney-Stratakis dyad. There are also several genes that have been associated with pheochromocytoma when it does not occur as part of a syndrome.

Signs and symptoms

Pheochromocytoma causes a variety of signs and symptoms, including (in alphabetical order):

• Abdominal pain
• Constipation
• Chest pain
• Dizziness
• Elevated blood sugar
• Facial flushing (redness)
• High blood pressure
• Increased respiratory rate
• Nausea
• Nervousness, anxiety, and irritability
• Pale skin tone
• Rapid heart rate and heart palpitations
• Severe headaches
• Sweating
• Visual disturbances
• Weight loss

Diagnosis

A health care provider uses blood and urine tests that measure catecholamines (pronounced kat-i-KOL-uh-meens) and/or their metabolites to diagnose pheochromocytoma.

Pheochromocytomas can secrete all, none, or any combination of catecholamines (epinephrine, norepinephrine, dopamine) and their metabolites, which are called metanephrines (metanephrine, normetanephrine, methoxytyramine). Multiple studies at the National Institutes of Health (NIH) have demonstrated the utility of measuring metanephrines in the blood for the diagnosis of pheochromocytoma/paraganglioma. This method is often recommended as the first diagnostic test when there is suspicion for a pheochromocytoma. Tumors can also be found accidentally during non-related imaging studies. The location of a pheochromocytoma can be determined by using several imaging methods, including computed tomography (CT) and magnetic resonance imaging (MRI).

CT scans use X-rays to produce detailed images of the inside of the body, while MRI uses magnetic waves to produce these pictures. A third imaging method that can be used to detect pheochromocytomas is MIBG (metaiodobenzylguanidine) scintigraphy. During this procedure, MIBG, a compound containing a small amount of radioactivity, is injected into a vein and is picked up by pheochromocytoma cells, but not normal cells.1 The body is scanned with a scanner that detects the MIBG. Any MIBG that is seen with the scanner can indicate the presence of pheochromocytoma cells.

Treatment

There are different types of treatment for patients with pheochromocytoma . Patients with pheochromocytoma that cause signs or symptoms are treated with drug therapy. Six types of standard treatment are used:

• Surgery
• Radiation therapy
• Chemotherapy
• Ablation therapy
• Embolization therapy
• Targeted therapy

Drug therapy begins when pheochromocytoma is diagnosed. This may include:

Drugs that keep the blood pressure normal. For example, one type of drug called alpha-blockers stops noradrenaline from making small blood vessels more narrow. Keeping the blood vessels open and relaxed improves blood flow and lowers blood pressure. Drugs that keep the heart rate normal. For example, one type of drug called beta-blockers stops the effect of too much noradrenaline and slows the heart rate. Drugs that block the effect of extra hormones made by the adrenal gland. Drug therapy is often given for one to three weeks before surgery. The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition.

• Iobenguane I 123 (Brand name: Adreview™) To be used in the detection of primary or metastatic pheochromocytomas or neuroblastomas as an adjunct to other diagnostic tests.
• Iobenguane I 131 (Brand name: Azedra) iobenguane I 131 (Azedra) was approved for the treatment of adult and pediatric patients 12 years and older with iobenguane scan positive, unresectable, locally advanced or metastatic pheochromocytoma or paraganglioma who require systemic anticancer therapy.

Surgery Surgery to remove pheochromocytoma is usually an adrenalectomy (removal of one or both adrenal glands). During this surgery, the tissues and lymph nodes inside the abdomen will be checked and if the tumor has spread, these tissues may also be removed. Drugs may be given before, during, and after surgery to keep blood pressure and heart rate normal.

After surgery to remove the tumor, catecholamine levels in the blood or urine are checked. Normal catecholamine levels are a sign that all the pheochromocytoma cells were removed.

If both adrenal glands are removed, life-long hormone therapy to replace hormones made by the adrenal glands is needed.

Prognosis

The overall 5-year survival in people with pheochromocytoma is estimated to be about 90%.There is increased life-time risk of secondary cancers (relative risk 3.63), with a slightly increased mortality risk according to a 2004 Swedish study of 481 patients.

Pheochromocytoma Resources
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NIH genetic and rare disease info

• NIH info on Pheochromocytoma

Pheochromocytoma is a rare disease.