Pheochromocytoma

Pheochromocytoma is an endocrine disorder that can be benign as well as malignant (in some cases) and may even cause death if left untreated. Know all about this uncommon neoplasm, including its possible causes, symptoms, diagnosis and treatment options.

What is Pheochromocytoma?

Doctors and medical researchers define Pheochromocytoma as a rare type of tumor that develops in one of the adrenal glands present in the body. It secretes excessive amounts of two hormones norepinephrine and epinephrine which control blood pressure, metabolism and heart rate. This leads to the development of numerous health issues in patients.

Pheochromocytoma Synonyms

The condition is also known by other names like:

Picture 1 – Pheochromocytoma

• Paraganglionoma
• Chromaffin tumors

Pheochromocytoma ICD 9 Code

The ICD 9 Code for this abnormal growth is 227.0.

Pheochromocytoma Incidence

As aforesaid, this is a rare type of tumor. It arises in only 0.05-0.2% of all hypertensive patients. This is usually a noncancerous (benign) growth that develops inside the core of an adrenal gland.

The condition can occur at any age. However, it arises most commonly in middle aged people.

Pheochromocytoma Symptoms

The usual signs and symptoms of this condition are:

• Chest pain
• Abdominal pain
• Palpitations
• Nervousness
• Pallor
• Sweating
• Irritability
• Faster heart rate
• Acute headache
• Loss of weight

Some individuals also suffer from other associated symptoms such as sleeping difficulties, high blood pressure and hand tremors. Such symptoms result from excessive production of chemical compounds (known as Catecholamines). The intensity of the problems depends on whether the compounds are being released constantly or in short spurts. The sporadic secretion of the epinephrine and norepinephrine hormones may also lead to the occurrence of a few other symptoms from time to time.

Pheochromocytoma Causes

Researchers are still in the dark regarding the exact cause why some adrenal gland cells turn into a tumor. However, they are certain that the tumors develop in special cells known as Chromaffin cells.

Each human body comprises of two adrenal glands, either located above each kidney. The adrenal glands, situated over the kidneys, produce the hormones noradrenaline (norepinephrine) and adrenaline (epinephrine) as well as the chemical compounds known as Catecholamines. The release of these hormones is generally triggered by physical and emotional stress. These hormones are needed by the body to maintain blood pressure and help individuals cope with situations that cause stress to them. The hormones provide almost every body organ and tissue with vital instructions.

In people with Pheochromocytoma, these glands tend to manufacture these hormones in high amounts. This elevates the heart rate and blood pressure in sufferers.

Pheochromocytoma Diagnosis

Although 90% cases of this condition are benign, Pheochromocytoma can become life-threatening for its patients if left undiagnosed and untreated. Its diagnosis usually begins with an examination of the physical condition of sufferers. This may be followed by one or more medical tests like:

• Abdominal CT scan
• MIBG scintiscan
• Catecholamines blood test
• Glucose test
• MRI of abdomen
• Metanephrine blood test
• Adrenal biopsy
• Urine catecholamines

Blood and urine tests help detect any increase in the levels of the hormones adrenaline (Epinephrine) and noradrenaline (Norepinephrine) and the products formed due to their decomposition (Metanephrines). You may require collecting samples of urine over a period of 24-hours for testing. If the tests suggest presence of a Pheochromocytoma, determining the location of the neoplasm is the next step for physicians.

Imaging scans are also effective in determining the presence if these growths. In most cases, an abdominal CT (computerized tomography) scan can help diagnose the tumor. However, doctors may also consider it essential to scan other regions of the body, such as the chest, pelvis and neck. Other scanning techniques, such as Metaiodobenzylguanidine (MIBG), Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) may also be effectual in detecting a Pheochromocytoma neoplasm.

Most small tumors in the adrenal gland are not Pheochromocytoma growths. These only require observation and not any treatment. However, a small percentage of adrenal tumors are actually found to be Pheochromocytoma tumors even in the absence of any signs and symptoms.

Pheochromocytoma and Genetic Testing

In some cases, the condition may arise due to genetic mutations. Doctors may suggest use of genetic testing in such individuals. The need of genetic testing, and the type of it that has to be conducted, depends on the location of the neoplasm and associated medical problems. You should seek genetic counseling if you have a family history of this tumor or any ailment that is associated with it. Counseling will help you understand whether you require Genetic testing.

Pheochromocytoma Differential Diagnosis

The differential diagnosis of Pheochromocytoma includes telling its symptoms apart from those of other disorders, such as:

• Anxiety disorders
• Essential hypertension
• Carcinoid
• Paragangliomas
• Paroxysmal supraventricular tachycardia
• Insulinoma
• Mercury poisoning
• Hyperthyroidism
• Renovascular hypertension

Pheochromocytoma Treatment

The treatment of this neoplasm involves its surgical removal. This is generally carried out after stabilizing the pulse and blood pressure of patients with the aid of medications. Patients may need to stay in hospital to let physicians monitor their vital signs closely. It is essential to monitor all the vital signs of patients continuously in an ICU setting. In cases where surgery fails to remove the tumor, it is necessary to use medications to manage it. A combination of drugs generally needs to be administered to sufferers to keep the effects of excess hormone production in check.

Chemotherapy and Radiation therapy have not been found to be effective in treating this type of neoplasm.

Doctors are likely to use medications if blood pressure cannot be lowered in patients, or if they cannot be surgically treated.

Pheochromocytoma and Medications

The drugs that are commonly used for the treatment of these tumors include:

Alpha blockers

Also known as Alpha-adrenergic antagonists or Alpha-adrenergic blocking agents, these medicines soothe some muscles that help tiny blood capillaries to remain open. These prevent the Noradrenaline (Norepinephrine) hormone from stimulating the muscles located in the walls of veins and smaller arteries. This stimulation leads to the constriction of the vessel walls. Blocking that effect help the vessels remain relaxed and open. This reduces blood pressure and also improves flow of blood in sufferers.

Doxazosin (Cardura), Terazosin (Hytrin), Prazosin (Minipress) and Phenoxybenzamine (Dibenzyline) are some alpha blockers that are often used for treatment of this tumor. Weight gain, headache, nausea and pounding heartbeat are some side effects arising due to an intake of these drugs.

Beta blockers

These drugs prevent the negative effects of the norepinephrine hormone and make the heart beat more slowly and with less intensity. It reduces the nerve impulses travelling through the heart. The heart requires less blood and oxygen, due to which it does not pump with much force. These medicines keep the blood vessels distended by reducing the release of the renin enzyme from the kidneys of sufferers.

These medicines are also known as beta-adrenergic blocking agents.Atenolol (Tenormin), Propranolol (Inderal LA, Innopran XL) and Metoprolol (Lopressor, Toprol XL) are some of the beta blockers that are commonly used for curing this tumor. These may give rise to various side effects, which may include headache, dizziness, fatigue and stomach upset.

Calcium channel blockers

These prevent entry of calcium into the heart and the walls of the blood vessels. In this way, these medicines reduce blood pressure and help widen and relax the blood vessels present in the arteries. Nicardipine (Cardene SR), Amlodipine (Norvasc) and diltiazem (Cardizem LA, Tiazac) are some of these medicines. Headache, drowsiness, constipation and rapid heartbeat (tachycardia) are some common side effects arising due to an intake of these drugs, also referred to as Calcium antagonists.

Metyrosine (Demser)

This drug reduces blood pressure by limiting the manufacture of catecholamines in the body. The medicine may be administered when other drugs have failed to improve the condition. Anxiety, depression, diarrhea and drowsiness are some of the side effects arising due to use of these drugs.

In patients of Pheochromocytoma, alpha blockers are first used to restore normalcy to blood pressure. Once blood pressure goes down, irregular or rapid heart rhythm can be controlled with beta blockers. One of these medicines may be used to make patients physically ready for this disease.

Pheochromocytoma and Surgery

The tumor is commonly treated by removing an entire adrenal gland that has been affected due to the condition. In most cases, operative cure is effective in relieving the discomforting symptoms of the neoplasm. Blood pressure generally returns to normalcy after operative removal of glands. Prior to surgery, medicines are administered for obstructing the harmful effects of adrenal hormones and for regulating blood pressure. In case tumors develop in both adrenal glands and both glands are surgically removed, patients may need taking medicines for substituting the other adrenal hormones.

Physicians may consider Laparoscopic surgery as a curative option on the basis of the location and size of the neoplasm. This surgery involves inserting instruments, such as a Laparoscope (a thin endoscope that helps examine the organs of the abdomen or even conduct a minor surgery), through various small incisions. The process requires a smaller incision than a conventional surgery and also results in a faster recovery. Laparoscopic surgery is being used more widely for treating Pheochromocytoma. However, it is not suitable for everyone. In case you are suffering from this tumor, you should discuss with your doctor whether this operative technique is appropriate for you.

In some cases, operative treatment may not be possible due to the manner of growth of the neoplasm or its dispersion (metastasis) to other areas of the body. In people with malignant (cancerous) cases of this tumor, treatment may not be only restricted to drugs and surgery. It may also involve chemotherapy, radiation or ablation of the arteries that supply blood to the neoplasm.

Pheochromocytoma Prognosis

Around 95% of patients with benign tumors have been found to live even 5 years after their surgical removal. The 5-years survival rate is less than 50% after surgery in malignant cases. With standard curative approach, high blood pressure can be controlled in sufferers. Following a successful operation, the level of the hormones epinephrine and norepinephrine returns to normalcy.

Pheochromocytoma Complications

Unless treated in time, these tumors (although non-cancerous) may give rise to severe complications. In some cases, the problems can be life-threatening. Very high blood pressure may result in abnormal heart rhythm (heart arrhythmia) or stroke, which can prove fatal for sufferers. Any reading that is higher than 180/110 millimeters of mercury (mm Hg) is regarded as very high blood pressure.

High blood pressure, occurring due to the condition, may also cause severe damage to many of the vital organs of patients by exerting excessive force on the walls of the artery. The more the blood pressure, and the greater duration for which it goes unchecked, the greater the risk of damage is.

Prolonged exposure to excess adrenal hormones may also lead to other problems, such as:

• Congestive heart failure
• Increased susceptibility to diabetes
• Damage to the cardiac muscles

In 25% patients, it may not be possible to cure high blood pressure after operation. The tumor is found to recur in around 10% cases of the condition. Heart problems, severe high blood pressure (Hypertension) and Cardiac arrest are other complications that are associated to this disease.

Pheochromocytoma Risk Factors

This tumor is more frequent in people aged between 30 and 50. Around 10% of these growths are observed in children. Often, these neoplasms arise equally in men and women. These are comparatively less frequently observed in blacks than people of other racial backgrounds. The tumor can be related to other disorders, such as:

Picture 2 – Pheochromocytoma Image

• Multiple endocrine neoplasia 2A and 2B
• Neurofibromatosis
• Medullary carcinoma of the thyroid
• Von Hippel-Lindau disease

If you are experiencing a sudden increase in blood pressure that refuses to be controlled by medications, and have a family history of MEN II, NF 1, Familial paraganglioma or Von Hippel-Lindau disease, get in touch with a healthcare provider immediately. Timely detection and treatment will help you recover from this condition faster and avoid its complications.

References:

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001380/

http://www.mdguidelines.com/pheochromocytoma

http://www.mayoclinic.com/health/pheochromocytoma/DS00569/

http://emedicine.medscape.com/article/124059-overview