PAROXYSTIC HYPERTENSION IN A LONG-TERM HEMODIALYZED PATIENT - SUCCESSFUL ADRENALECTOMY FOR A DOPAMINE-PRODUCING PHEOCHROMOCYTOMA

Pheochromocytoma (Pheo) is an uncommon neoplasm producing blood pressure troubles and it may be undiagnosed in chronic dialyzed patients in whom hypertension is a common finding. The symptoms in Pheo syndrome depends on the prevalent catecholamine released, the most common being epinephrine (E) and norepinephrine (NE). Recently, a particular clinical picture has been described for dopamine (DA)-producing Pheos, in whom a normo-hypotensive status is more often observed. The authors report a case of mainly dopamine-producing Pheo in a long-term dialyzed patient, successfully treated with adrenalectomy. The main steps in diagnosis and preoperative management are described and debated also in view of the particular background produced by the end-stage renal failure. The common imaging techniques adopted for adrenal medullary neoplasms (US, CT, MIBG scintiscan) confirmed to be decisive for diagnosis; HPLC assay of plasma catecholamines is the only biochemical test available in these patients although its significance is questionable due to the poor knowledge of catecholamine metabolism in chronic renal failure. The clinical findings observed in this case seem in disagreement with those already reported in DA producing Pheos. Pheo in hemodialyzed patients is a rare event and it may be hidden by other more common causes of hypertension. However, more awareness from the medical staff allows to diagnose the neoplasm correctly by the currently available methods and to plan a safe surgical therapy also in high-risk patients.