Pheochromocytom a Caira Guese Mariya Kirillova
Pheochromocytoma Pheochromocytoma is a rare, usually benign tumor that develops in an adrenal gland. Usually, this type of tumor affects one of your two adrenal glands, but it can affect both. If you have pheochromocytoma, the tumor releases hormones that cause either episodic or persistent high blood pressure. Untreated, a pheochromocytoma can result in severe or life-threatening damage to other body systems, especially the cardiovascular system.
Adrenal Glands The adrenal glands, also called the suprarenal glands, are a significant part of the endocrine system. The paired adrenal glands are triangular shaped organs that measure approximately 5 cm by 2 cm, are located on the superior aspect of each kidney, and weigh 4 to 5 grams each.
Adrenal Glands Pheochromocytomas arise from the central portion of the adrenal gland, which is called the adrenal medulla. The adrenal medulla is responsible for the normal production of adrenaline, which our body requires to help maintain blood pressure and to help cope with stressful situations. A tumor that arises from the adrenal medulla and overproduces adrenaline can be a deadly tumor because of the severe elevation in blood pressure it causes.
Etiology ● Majority of pheochromocytomas are sporadic, approximately 30% result from inherited mutations. ● To date, 10 genes associated with pheochromocytoma and paraganglioma have been identified. ● Familial syndromes associated with pheochromocytomas include MEN 2A and 2B, neurofibromatosis (von Recklinghausen disease), and VHL disease, as well as others.
MEN 2 The MEN 2A and 2B syndromes have been traced to germline mutations in the ret proto-oncogene on chromosome 10, which encodes a tyrosine kinase receptor involved in the regulation of cell growth and differentiation. Pheochromocytomas occur bilaterally in the MEN syndromes in as many as 70% of cases. Novel mutations that cause hereditary pheochromocytoma have been identified in the MYC- associated factor X ( MAX ) gene. Loss of MAX function is correlated with metastatic potential. Mutations in MAX are responsible for approximately 1% of pheochromocytomas and paragangliomas. GDNF gene, are associated with development of adrenal or extra-adrenal pheochromocytomas. TMEM127 gene also is associated with susceptibility to pheochromocytoma. Several families have been described with unique mutations to this gene that have resulted in the development of pheochromocytoma between young adulthood and middle age.
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- Fall '19