Pheochromocytoma predominantly secretes which hormone: September 2007

Ans. C: Nor-epinephrine Relative catecholamine levels also differ in pheochromocytomas. Most pheochromocytomas secrete norepinephrine predominantly, whereas secretions from the normal adrenal medulla are composed of roughly 85% epinephrine. Familial pheochromocytomas are an exception because they secrete large amounts of epinephrine. Thus, the clinical manifestations of a familial pheochromocytoma differ from those of a sporadic pheochromocytoma.