Normotensive Pheochromocytoma: Institutional Experience

We report an audit of nine cases of subclinical or normotensive pheochromocytoma managed in our department. This is the first report from India of such a series. During the period 1990–2003 a total of 45 patients of pheochromocytoma were diagnosed and managed in the Department of Endocrine Surgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences. Among them, nine patients were diagnosed as having subclinical or normotensive pheochromocytoma. Inclusion criteria for normotensive pheochromocytoma were: no previous history of hypertension clinically and, in the previous treatment documents, any episode of symptoms suggesting high blood pressure. The demographic profile, clinical presentation, biochemical investigations, imaging results, surgical notes, and follow-up record were reviewed retrospectively. All patients had a primary complaint of flank/abdominal pain and were normotensive. Seven had elevated urinary metanephrine levels, and one patient had normal values. One patient did not undergo the urinary metanephrine assay. Imaging of the abdomen showed seven adrenal and two extra-adrenal masses (eight had computed tomography scans of the abdomen, and one underwent ultrasonography). After selective α-adrenergic blockade (prazosin), surgery was performed. Six patients required infusion of sodium nitroprusside intraoperatively. The final histopathology was pheochromocytoma in all patients. Metanephrine levels were normal during the follow-up. Normotensive pheochromocytomas are a distinct entity, and all adrenal incidentalomas should be investigated for catecholamine hypersecretion. We support the use of preoperative α-adrenergic blockade, and these patients should be treated along the same lines as hypertensive pheochromocytoma.