What is pheochromocytoma?
Pheochromocytomas are a type of tumor of the adrenal glands that can release high levels of epinephrine and norepinephrine. As the name implies, the adrenalglands are located near the "renal" (kidney) area. One adrenal gland sits on top of each of the two kidneys.
Despite their small size, the adrenal glands have many functions. They are complex endocrine (hormone secreting) glands. Cells in different regions of the adrenal glands have different functions in the endocrine system.The outer portion of the adrenal gland is called the adrenal cortex. In part of the adrenal cortex (zona fasciculata and zona reticularis) the cells secrete cortisol, a hormone similar to cortisone, which is essential for handling stresses In another area (zona glomerulosa) cells secrete a hormone called aldosterone which helps in water and salt regulation and blood pressure control.
The inner area of the adrenal gland is referred to as the adrenal medulla. This is where the cells secrete substances called catecholamines -- epinephrine, norepinephrine and dopamine. These are "flight or fight" hormones. They are responsible in part for that feeling of an "adrenaline" rush people feel when they are afraid. It is these cells that are overproduced by a pheochromocytoma. Basically, a pheochromocytoma is a tumor of these catecholamine-secreting cells, and that causes the clinical signs and symptoms we will discuss below. The catecholamine-secreting cells are sometimes referred to as chromaffin cells, and they are found in other areas of the body as well as in the adrenal medulla.
Sometimes, pheochromocytomas arise from chromaffin cells that are located outside of the adrenal gland. In this case, they are termed extra-adrenal pheochromocytomas or paragangliomas and are usually located in the abdomen.
Pheochromocytomas may occur in persons of any age. The peak incidence is between the third and the fifth decades of life. Pheochromocytomas are, fortunately, quite rare, and most of them are benign.
What are the symptoms for pheochromocytoma?
Fast heartbeat symptom was found in the pheochromocytoma condition
Signs and symptoms of pheochromocytomas often include:
- High blood pressure
- Heavy sweating
- Rapid heartbeat (tachycardia)
- Paleness in the face (pallor)
- Shortness of breath (dyspnea)
Less common signs or symptoms may include:
- Anxiety or sense of doom
- Weight loss
Triggers of symptomatic spells
Spells may occur spontaneously or may be triggered by such factors as:
- Physical exertion
- Anxiety or stress
- Changes in body position
- Labor and delivery
- Surgery and anesthesia
Foods high in tyramine, a substance that affects blood pressure, also can trigger a spell. Tyramine is common in foods that are fermented, aged, pickled, cured, overripe or spoiled. These foods include:
- Some cheeses
- Some beers and wines
- Dried or smoked meats
Certain medications that can trigger a symptomatic spell include:
- Monoamine oxidase inhibitors (MAOIs), such as phenelzine (Nardil), tranylcypromine (Parnate) and isocarboxazid (Marplan)
- Stimulants, such as amphetamines or cocaine
When to see a doctor
The signs and symptoms of pheochromocytoma can be caused by a number of conditions. So it's important to get a prompt diagnosis.
Although high blood pressure is a primary sign of a pheochromocytoma, most people with high blood pressure don't have an adrenal tumor. Talk to your doctor if any of the following factors are relevant to you:
- Difficulty controlling high blood pressure with current treatment plan
- A family history of pheochromocytoma
- A family history of a related genetic disorder: multiple endocrine neoplasia, type II (MEN II); von Hippel-Lindau disease; familial paraganglioma or neurofibromatosis 1 (NF1)
What are the causes for pheochromocytoma?
Researchers don't know what causes a pheochromocytoma. The tumor develops in specialized cells, called chromaffin cells, situated in the center of an adrenal gland. These cells release certain hormones, primarily adrenaline (epinephrine) and noradrenaline (norepinephrine), that help control many body functions, such as heart rate, blood pressure and blood sugar.
The role of hormones
Adrenaline and noradrenaline are hormones that trigger your body's fight-or-flight response to a perceived threat. The hormones prompt higher blood pressure, a faster heart rate and a boost in other body systems that enable you to react quickly. A pheochromocytoma results in the irregular and excessive release of these hormones.
While most chromaffin cells reside in the adrenal glands, small clusters of these cells are also in the heart, head, neck, bladder, back wall of the abdomen and along the spine. Tumors in these chromaffin cells, called paragangliomas, may result in the same effects on the body.
What are the treatments for pheochromocytoma?
Pheochromocytomas can be a component of certain familial or genetic syndromes. The most common familial condition is called multiple endocrine neoplasia, or MEN for short. Two types of MEN -- MEN 2A and 2B -- are associated with pheochromocytomas. Both are genetic syndromes that run in families and are transmitted from parent to child in an autosomal dominant manner.
Pheochromocytomas are not the only tumors that occur in MEN 2A and 2B. MEN 2A carries an increased risk of tumors of the parathyroids, glands near the thyroid that help to regulate calcium levels in the body. And both MEN 2A and 2B elevate the risk of medullary carcinoma of the thyroid - an unusual type of thyroid cancer. In families where MEN is suspected, genetic testing can be done to help identify family members at risk.
Pheochromocytomas are a feature of other genetic disorders, including von Hippel-Lindau syndrome and neurofibromatosis type 1. Both of these disorders are associated with the development of numerous benign and malignant tumors.
There are also many individuals who have pheochromocytomas with no known family history of them. These cases are termed sporadic. In general, if these patients have bilateral disease (pheochromocytomas in both adrenal glands) or are diagnosed before the age of 21, genetic screening is recommended.
What are the risk factors for pheochromocytoma?
People with rare inherited disorders have an increased risk of developing a pheochromocytoma or paraganglioma, and tumors associated with these disorders are more likely to be cancerous. These genetic conditions include the following:
- Multiple endocrine neoplasia, type II (MEN II) is a disorder resulting in tumors in more than one part of the body's hormone-producing (endocrine) system. Other tumors associated with MEN II can appear on the thyroid, parathyroid, lips, tongue and gastrointestinal tract.
- Von Hippel-Lindau disease can result in tumors at multiple sites, including the central nervous system, endocrine system, pancreas and kidneys.
- Neurofibromatosis 1 (NF1) results in multiple tumors in the skin (neurofibromas), pigmented skin spots and tumors of the optic nerve.
- Hereditary paraganglioma syndromes are inherited disorders that result in either pheochromocytomas or paragangliomas.