A Review and Analysis of Pheochromocytoma

Introduction:

Pheochromocytoma is a rare condition affecting approximately five out of every one million people (0.0005%) of the population. On average, there are 1000 cases diagnosed per year in the United States. Pheochromocytomas are neuroendocrine tumors that are responsible for an up-regulation of the entire sympathetic nervous system (SNS). These tumors reside mostly in the medulla and adrenal glands; however, some do arise in extra-adrenal chromaffin tissue (Zelinka 2011). Pheochromocytoma generally refers to the tumors within the medulla and adrenal glands, while the extra-adrenal areas are referred to as paraganglioma. Common locations for paraganglioma consist of the heart, along the spinal cord, back wall of the abdomen, the neck, and the bladder. Pheochromocytomas originate in chromaffin cells, which are responsible for producing catecholamines. Therefore, pheochromocytomas secrete high levels of catecholamines, primarily norepinephrine along with a lesser amount of epinephrine. Norepinephrine is the primary stimulant of the sympathetic nervous system, thus this explains how these tumors can cause near-constant activation of the SNS resulting in a wide array of symptoms. The majority of pheochromocytomas are benign tumors (~90%); however, they can be malignant and are vastly more troublesome if they are. Interestingly, extra-adrenal pheochromocytomas (paragangliomas) are the most likely to become malignant tumors. Most cases have no identifiable cause, but up to 25% of cases are being attributed to heredity. The only treatment method currently available for a patient with pheochromocytoma(s) is surgery. Both benign and malignant tumors are necessary to remove as the patient’s blood pressure is in jeopardy with these ...

... middle of paper ...

...e (PMNT) (Pacak 2011). Thus, with a tumor of chromaffin cells, this process can occur much more often leading to a massive increase in catecholamine production.

Conclusion:

In conclusion, while pheochromocytoma may be an extremely rare condition, it is also a serious issue that deserves attention. Due to its vast array of symptoms it is difficult to diagnosis properly. With genetics only explaining 25% of possible cases, there is still an immense amount of information to learn about this condition. Moreover, with how rare this condition is and genetics only being identified as 25% of cases, it’s astonishing that there are already at least six genes directly responsible with a few others having supporting effects. Additionally, it’s amazing that 90% of cases are benign tumors as the five year survival rate is superb compared to the malignant five year survival rate.