1. 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. Pheochromocytoma is often hereditary, not only in phacomatoses (Hippel-Lindau disease, neurofibromatosis, and familial endocrine neoplasia), but also as an isolated defect [MIM*171300] as an autosomal dominant trait.
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