Urinary Vanillylmandelic Acid Levels in the Workup of Adrenal Incidentaloma

Abstract

Introduction Although the majority of patients with pheochromocytoma have hypertension, 515% of patients are normotensive and this percentage may be higher in patients with adrenal “incidentalomas”. 1-3 The diagnosis of asymptomatic pheochromocytoma is increasing in incidence, most likely due to widespread use of sectional imaging. 4 The most reliable method for diagnosing pheochromocytoma or paraganglioma is measurement of 24-hour urine catecholamines and metanephrines, with a sensitivity and specificity of roughly 98%. 5-7 The urinary vanillylmandelic acid level though may retain some value in the diagnosis of pheochromocytoma, particularly when paired with characteristic findings on imaging.