Emmanuel L. Bravo, MD
Bravo E.; Plasma or Urinary Metanephrines for the Diagnosis of Pheochromocytoma? That Is the Question. Ann Intern Med. 1996;125:331-332. doi: 10.7326/0003-4819-125-4-199608150-00012
Download citation file:
Published: Ann Intern Med. 1996;125(4):331-332.
Several clinical disorders mimic the signs and symptoms of pheochromocytoma; the definitive diagnosis of this condition thus rests primarily on showing excessive and inappropriate production of catecholamine. Because pheochromocytoma is fatal if undiagnosed, biochemical tests used to detect it should have a high sensitivity. In addition, the predictive value of any negative test result should exclude false-negative results as efficiently as possible. A false-positive result is relatively less important because additional testing (using, for example, clonidine suppression, glucagon stimulation, and imaging techniques) can be done to rule out the disease.
In an article recently published in Annals , Lenders and colleagues reported that tests for measuring plasma metanephrine levels are more sensitive than tests for measuring plasma catecholamine levels and 24-hour urinary metanephrine levels (sensitivities of 100%, 85%, and 89%, respectively). In this study, the negative predictive value of a normal plasma metanephrine level was 100%. Despite these promising results, the study was limited by the lack of a reference group of patients with panic disorder, β-adrenergic hyperresponsiveness, labile essential hypertension, extra-adrenal tumors, and hereditary endocrine syndromes. In addition, Lenders and colleagues measured urinary metanephrine levels using a colorimetric assay that is inferior to high-performance liquid chromatography. Similarly, high-performance liquid chromatography yields higher plasma catecholamine values than do radioenzymatic techniques. This could explain why Lenders and colleagues found that measurement of plasma catecholamine levels had a lower diagnostic sensitivity for pheochromocytoma.
to gain full access to the content and tools.
Learn more about subscription options.
Register Now for a free account.
Endocrine and Metabolism, Hematology/Oncology, Adrenal Disorders, Endocrine Cancer.
Results provided by:
Copyright © 2016 American College of Physicians. All Rights Reserved.
Print ISSN: 0003-4819 | Online ISSN: 1539-3704
Conditions of Use
This PDF is available to Subscribers Only