Following is true about pheochromocytoma except –
Correct Answer: 90% of non familial cases are bilateral
Description: Ans. is 'c' i.e., 90% of non familial cases are bilateral Pheochromocvtomao Pheochromocytoma is a neoplasm of chromaffin ceils which usually arise from adrenal medulla,o About 10% of these tumors arise at extraadrenal sites, where they are called paraganglioma :-o When pheochromacytomas arise at extra-adrenal site, they are referred to as paraganglioma.o Paravertebral paragangliomas secrete catecholamines.Pheochrom ocvtomao The tumor is composed of polygonal to spindle shaped chromaffin cells or chief cells, clustered with sustentacular cells into small nests or alveoli (zellballen) by a rich vascular network. The nuclei are usually round to ovoid, with a stippled " salt & pepper" chromatin that is characteristic of most neuroendocrine tumors,o Zellballen pattern are seen in paraganglioma.Pheochromacytomas usually subscribe to a convenient "rule of 10s" :-10% of pheochromocytomas arise in association with one of several familial syndromes. These include the MEN-2A & MEN-2B syndromes, type I neurofibromatosis, von Hippel-Lindau syndrome & Sturge-Weber syndrome. 10% of pheochromocytomas are extra-adrenal, occurring in sites such as organ of Zuckerkandl & carotid body, where these chromaffin-negative tumors are usually called paragangliomas to distinguish them from pheochromoc ytomas.10% of nonfamilial adrenal pheochromocytomas are bilateral: this figure may rise to 70% in cases that are associated with familial syndromes.10% of adrenal pheochromocytomas are biologically malignant although the associated hypertension represents a serious & potentially lethal complication of even "'benign"tumors.10% of adrenal pheochromocytomas arise in childhood, usually the familial subtypes, and with a strong male preponderance. The nonfamilial pheochromocytomas most often occur in adults between 40 & 60 years of age, with a slight female preponderance.
Category:
Pathology
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