pheochromocytoma

A functional chromaffinoma, usually benign, derived from adrenal medullary tissue cells and characterized by the secretion of catecholamines, resulting in hypertension, which may be paroxysmal and associated with attacks of palpitation, headache, nausea, dyspnea, anxiety, pallor, and profuse sweating. P. is often hereditary, not only in phacomas such as Hippel-Lindau disease, neurofibromatosis, and familial endocrine neoplasia, but also as an isolated defect [MIM*171300] as an autosomal dominant trait. SEE ALSO: paraganglioma.

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pheo·chro·mo·cy·to·ma or Brit phaeo·chro·mo·cy·to·ma .fē-ə-'krō-mə-sə-'tō-mə, -sī- n, pl -mas also -ma·ta -mət-ə a tumor that is derived from chromaffin cells and is usu. associated with paroxysmal or sustained hypertension

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pheo·chro·mo·cy·to·ma (fe″o-kro″mo-si-toґmə) [pheochromocyte + -oma] a usually benign, well-encapsulated, lobular, vascular tumor of chromaffin tissue of the adrenal medulla or sympathetic paraganglia. Because of increased secretion of epinephrine and norepinephrine, hypertension is a cardinal symptom; it may be persistent or intermittent. During severe attacks, there may be headache; sweating; palpitation and tremor; pallor or flushing of the face; nausea and vomiting; pain in the chest and abdomen; and paresthesias of the extremities. Called also medullary chromaffinoma, medullary paraganglioma, chromaffin cell tumor, and pheochromoblastoma.