[Pheochromocytoma and adrenomedullary hyperplasia]

A comparison was made on the main clinical features between 6 cases of benign pheochromocytoma and 4 cases of adrenomedullary hyperplasia admitted in to our hospital from 1981 to 1986. It is found that differentiation between pheochromocytoma and adrenomedullary hyperplasia with symptoms or signs alone is difficult, since both may have the same symptoms such as paroxysmal or sustained hypertension elevation and shock. Moreover, the laboratory findings of the former were also similar to those of the latter. So the diagnosis of both was suspected upon clinical manifestations and confirmed with biochemical investigation. If an enlarged adrenal silhouetteis shown on one side or both sides with no tumor mass, as evidenced by retroperitoneal pneumography, computerized tomography, nuclear magnetic resonance, ultrasonography or 131I-meta-iodobenzyl-guanidine (131I-mIBG), adrenomedullary hyperplasia might be considered. Confirmatory differential diagnosis between the pheochromocytoma and adrenomedullary hyperplasia perhaps can only be made after surgical exploration and pathological examination. Pheochromocytoma is usually benign and can be excised totally after medical preparation with an alpha-adrenergic antagonist as we have done; adrenomedullary hyperplasia can only be treated with subtotal adrenalectomy. We also agree with the idea that preoperative alpha-adrenergic blockage would reduce surgical complication and mortality. It is generally recommended that a beta-adrenergic antagonist, such as propranolol, be given only after effective alpha-adrenergic blockade is established because beta-adrenergic blockade alone may exacerbate hypertension as a result of unopposed alpha-adrenergic stimulation. Besides operation, 131I-mIBG administration seems to be a promising alternative method for malignant pheochromocytoma or adrenomedullary hyperplasia.