For over a decade, we have been offering support and information for pheochromocytoma and related conditions. Our group is the original support group, started in 1997 by several persons who had direct or indirect experience with pheochromocytoma and related conditions. We have a large and active support board where a great deal of practical and up to date information can be found.
Pheochromocytomas are catecholamine producing tumors of chromaffin cells, that can occur sporadically or as part of a familial syndrome. Although the majority are found in the adrenal glands, pheochromocytoma can basically be found wherever chromaffin tissue can be found. Ninety-seven percent have been found in the abdomen, 2% in the thorax and 1% in other regions.
The tumor is named for its colorful reaction in fixatives containing chromic acid salts. In modern day language, these tumors are often referred to as "pheos". Most pheos secrete a number of hormones, including norepinephrine, epinephrine, dopamine, vanylmandelic acid, and metanephrines. Pheochromocytomas are usually benign (non-cancerous), but can cause dangerously high blood pressure and other symptoms, including pounding headaches, heart palpitations, flushing of the face, and nausea. Pheochromocytoma symptoms usually include paroxysms of extreme hypertension, accompanied by sweating, headache, and other autonomic disturbances, probably resulting from physical compression and/or ischemia of the "pheo". Doctors and patients often refer to these bouts as "episodes".
Pheochromocytomas can be found anywhere in the body, though most occur in the adrenal medulla. Even a tiny benign pheochromocytoma can make a person very sick. Regardless of location and appearance, the patients will usually report anxiety, headache, palpitations, panic attacks, sweating, and dizziness as some of the main symptoms. Extra-adrenal paragangliomas (often called extra-adrenal pheochromocytomas) are closely related and less common tumors. These tumors originate in the ganglia of the sympathetic nervous system and are named based upon the primary anatomical site of origin.
It is estimated that approximately ten to twenty-five percent of pheochromocytoma cases are genetic. There are a number of these genetic types of conditions, including Multiple Endocrine Neoplasia Syndromes, Von Hippel-Lindau, Von Recklinghausen's Neurofibromatosis, Succinic Dehydrogenase Mutation. One of the MENS illnesses which is now called MEN2A was once called MEA, or Multiple Endocrine Adenoma Syndrome. More thorough information about all of these conditions can be found in our information links and support message boards shown on the left sidebar.
The Pressor definition of pheochromocytoma:
"Pheochromocytomas are neuroendocrine tumors derived from catecholamine-producing chromaffin cells of the adrenal medulla, whereas extra-adrenal paragangliomas arise from chromaffin cells of the extra-adrenal paraganglia (a pheochromocytoma is an intra-adrenal paraganglioma). It was agreed to adopt the 2004 WHO classification of endocrine tumors where pheochromocytomas are defined as tumors arising from catecholamine-producing chromaffin cells in the adrenal medulla. According to this classification, closely related tumors of extra-adrenal sympathetic and parasympathetic paraganglia are classified as extra-adrenal paragangliomas. The recommendation to adopt this simplified definition was based on the need for international standardization. However, as long as the istopathological and clinical entities are well-defined and accounted for, for purposes of genetic testing the two types of tumors should often be considered together because they often have a common genetic basis."
The Endotext version/discussion of the definition of pheochromocytoma in more thorough details:
"Pheochromocytomas are chromaffin cell tumors that produce, store, metabolize, and secrete catecholamines. The metabolism of catecholamines is a more consistent process than that of catecholamine secretion. The 2004 World Health Organization classification of endocrine tumors defines pheochromocytoma as a tumor arising from catecholamine-producing chromaffin cells in the adrenal medulla — an intra-adrenal paraganglioma. Closely related tumors of extra-adrenal paraganglia are classified as extra-adrenal paragangliomas. While these definitions serve to distinguish the two types of tumor based on location, this does not take into account differences in functional characteristics related to other differences in cellular origin. More specifically, while extra-adrenal paragangliomas derived from sympathetic nervous system-associated chromaffin tissue almost always produce catecholamines and often lead to hypertension, those derived from parasympathetic tissue (mainly head and neck paragangliomas) produce significant amounts of catecholamines in only less than 5% and usually do not cause hypertension. It therefore seems likely that pheochromocytomas will be continued to be defined as catecholamine-producing tumors of intra- and extra-adrenal chromaffin cells, with those derived from from the latter types of chromaffin cells classified as extra-adrenal pheochromocytomas. Pheochromocytomas typically occur in about 85% of cases from adrenal medullary chromaffin tissue and in about 15% of cases from extra-adrenal chromaffin tissues. Extra-adrenal pheochromocytomas in the abdomen most commonly arise from a collection of chromaffin tissue around the origin of the inferior mesenteric artery (the organ of Zuckerkandl) or aortic bifurcation. Most pheochromocytomas represent sporadic tumors and about 20-30% of pheochromocytomas are familial. Sporadic pheochromocytomas are usually unicentric and unilateral while familial pheochromocytomas are often multicentric and bilateral. Both adrenal and extra-adrenal paragangliomas display similar histopathological characteristics. Unusual sites in the abdomen and pelvis include kidney, urethra, prostate, spermatic cord, genital tract, and liver. About 4-10% of patients with pheochromocytoma present with adrenal incidentaloma, whereas approximately 5% are diagnosed at surgery. Although metastases may be rare for adrenal (about 10%) and familial (less than 5%) pheochromocytomas, the prevalence is up to 36-50% for extra-adrenal abdominal pheochromocytomas. Finally, up to 10% of intra-adrenal pheochromocytomas show local recurrence. Pheochromocytomas occur in about 0.05% to 0.1% of patients with sustained hypertension. However, this probably accounts for only 50% of persons harboring pheochromocytoma, when it is considered that about half the patients with pheochromocytoma have only paroxysmal hypertension or are normotensive. Also, it must also be considered that the prevalence of sustained hypertension in the adult population of Western countries is between 15% to 20%. Thus, in Western countries the prevalence of pheochromocytoma can be estimated to lie between 1:6,500 to 1:2,500 with an annual incidence in the United States of 500 to 1,100 cases per year. Despite this low incidence, pheochromocytoma must always be considered since if it is identified the condition can be cured in about 90% cases, whereas left untreated the tumor is likely to be fatal due catecholamine-induced malignant hypertension, heart failure, myocardial infarction, stroke, ventricular arrhythmias, or metastatic disease."