Advances in the diagnosis and treatment of pheochromocytoma.

Diagnosis and management of pheochromocytoma, once dangerous and uncertain, have been dramatically altered in recent years by advances in imaging, assays, and pharmaceuticals. During the past ten years we have treated 18 patients who had pheochromocytoma. Biochemical diagnosis was made in all patients by measurement of 24-hour urinary total catecholamine excretion or by epinephrine-norepinephrine fractionation. Determination of epinephrine-norepinephrine ratios was instrumental in making the diagnosis of pheochromocytoma in two patients in whom total catecholamine levels were normal. Localization of the pheochromocytoma in the most recently treated cases was accomplished by ultrasound, computed tomography, or iodine I 131 iobenguane (iodine I 131 metaiodobenzylguanidine) scanning. Nine patients in the series were prepared for surgery with phenoxybenzamine hydrochloride and six with prazosin hydrochloride. Preoperative total alpha-adrenergic blockade with phenoxybenzamine offered no advantage over selective blockade with prazosin in terms of perioperative fluid requirements or intraoperative hemodynamic stability.