Biochemical Tests for Pheochromocytoma: Strategies in Hypertensive Patients.

OBJECTIVE: To determine the optimal clinical strategy utilizing either 1) serum catecholamines, 2) urinary metanephrines, or 3) urinary vanillylmandelic acid measurements in the evaluation of hypertensive patients with suspected pheochromocytoma. DESIGN: Prospective clinical determination of test-operating characteristics. SETTING: Tertiary care university medical center. PATIENTS/PARTICIPANTS: 415 patients referred for evaluation of suspected pheochromocytoma. INTERVENTIONS: All subjects had measurements of the three above-mentioned biochemical tests with the diagnosis of pheochromocytoma established by tissue confirmation. RESULTS: All three biochemical tests were similar in sensitivity (0.70-0.75), specificity (0.90-0.95), and receiver operating characteristics. With an estimated disease prevalence of 5.9% in symptomatic hypertensive patients, the predictive value of any single negative test would be 98% in ruling out disease. CONCLUSIONS: All three biochemical tests have similar performance characteristics and only a single test need be performed to exclude pheochromocytoma in most symptomatic hypertensive patients in a primary care population