A paraganglioma is rare neuroendocrine neoplasm that may develop at various body sites (including the head, neck, thorax and abdomen). About 97% are benign and cured by surgical removal; the remaining 3% are malignant because they are able to produce distant metastases. "Paraganglioma" is now the most-widely accepted term for these lesions, that have been also described as: glomus tumor, chemodectoma, perithelioma, fibroangioma, and sympathetic nevi.
Most paragangliomas are either asymptomatic or present as a painless mass. While all contain neurosecretory granules, only in 1–3% of cases is secretion of hormones such as catecholamines abundant enough to be clinically significant; in that case manifestations are:
- Neck mass
- Cranial nerve palsies
- Hearing loss
- Swallowing difficulty
- Reddish bulge behind eardrum
- Brown's sign
Researchers don't know exactly what causes the development of a pheochromocytoma. They do understand that the tumor develops in specialized cells, called chromaffin cells, located in the center of an adrenal gland. These cells produce and release certain hormones, primarily adrenaline (epinephrine) and noradrenaline (norepinephrine).
The role of hormones
Adrenaline and noradrenaline are hormones that normally function as the trigger for 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 with a burst of energy. 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 located 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.
There is no specifique prevention of paraganglioma.
To measure the levels of cathecholamines and metanephrines.they can be mesured in the Plasma (Blood) or in 24 hour urinne collection.
Once the diagnosis is confirmed in the Plasma or in the urine, the patient schould have a CAT scan or MRI to identify the position of the paraganglioma.
Paraganglioma is rare tumor with a poor prognosis.
The primary treatment for a pheochromocytoma is surgery to remove the tumor. Before you undergo surgery, your doctor will prescribe medications to stabilize your blood pressure and lower the risk of complications during surgery.
You will likely take two different drugs for a period of seven to 10 days that help lower blood pressure before surgery.
- Alpha blockers prevent noradrenaline from stimulating the muscles in the walls of smaller arteries and veins. Because these blood vessels remain open and relaxed, blood flow improves and blood pressure lessens. Examples of alpha blockers include phenoxybenzamine (Dibenzyline), doxazosin (Cardura), prazosin (Minipress) and terazosin (Hytrin). Side effects may include irregular heartbeat, dizziness, fatigue, vision problems, sexual dysfunction in men and swelling in your limbs.
- Beta blockers, which inhibit the effect of adrenaline, result in your heart beating more slowly and with less force. Beta blockers also help keep blood vessels open and relaxed by slowing the release of a particular enzyme from your kidneys. Examples of beta blockers include atenolol (Tenormin), metoprolol (Lopressor, Toprol) and propranolol (Inderal, Innopran). Side effects may include fatigue, upset stomach, headache, dizziness, constipation, diarrhea, irregular heartbeat, difficulty breathing and swelling in the limbs.
- Other medications that lower blood pressure may be prescribed if your blood pressure is not stabilized with alpha blockers and beta blockers.
In most cases, the entire adrenal gland with a pheochromocytoma is removed with laparoscopic, or minimally invasive, surgery. Your surgeon will make a few small openings through which he or she inserts wand-like devices equipped with video cameras and small tools.
The remaining healthy adrenal gland carries out the functions normally performed by two, and blood pressure usually returns to normal.
In some unusual situations, such as when the other adrenal gland has already been removed, a surgery may be considered to extract only the tumor and spare some of the healthy tissue.
If a tumor is cancerous (malignant), surgery may be effective only if the tumor and any metastasized tissues are isolated. However, even if all of the cancerous tissues are not removed, surgery may limit hormone production and provide some control of blood pressure.
As cancer is rare among cases of pheochromocytoma, the research about the best treatments is still relatively limited. Treatments for malignant tumors and metastasized cancer related to a pheochromocytoma may include the following:
- Radionuclide treatment. This radiation therapy combines MIBG, a compound that attaches to adrenal tumors, with a type of radioactive iodine. The treatment goal is to deliver radiation therapy to a specific site and kill cancerous cells
- Chemotherapy. Chemotherapy is the use of powerful drugs that kill fast-growing cancer cells.
- Targeted cancer therapies. These medications inhibit the function of naturally occurring molecules that promote the growth and spread of cancerous cells.