A Comparison of Biochemical Tests for Pheochromocytoma: Measurement of Fractionated Plasma Metanephrines Compared with the Combination of 24-Hour Urinary Metanephrines and Catecholamines

Plasma chromogranin A or urine fractionated metanephrines follow-up testing improves the diagnostic accuracy of plasma fractionated metanephrines for pheochromocytoma.

CONTEXT The initial diagnosis of pheochromocytoma relies on plasma fractionated metanephrines levels. Normal levels exclude pheochromocytoma, but positive tests have a low positive predictive value due to the disease's rarity. OBJECTIVES The objective of the study was to evaluate three approaches to distinguish between true-positive and false-positive tests: 1) increased cutoff for plasma fra...

Plasma Metanephrines in the Diagnosis of Pheochromocytoma

Plasma metanephrines in the diagnosis of pheochromocytoma.

OBJECTIVE To examine whether tests for plasma metanephrines, the o-methylated metabolites of catecholamines, offer advantages for diagnosis of a pheochromocytoma over standard tests for plasma catecholamines or urinary metanephrines. DESIGN Cross-sectional study. SETTING 3 clinical specialist centers. PATIENTS 52 patients with a pheochromocytoma; 67 normotensive persons and 51 patients wi...

Biochemical diagnosis of pheochromocytoma: which test is best?

CONTEXT Diagnosis of pheochromocytoma depends on biochemical evidence of catecholamine production by the tumor. However, the best test to establish the diagnosis has not been determined. OBJECTIVE To determine the biochemical test or combination of tests that provides the best method for diagnosis of pheochromocytoma. DESIGN, SETTING, AND PARTICIPANTS Multicenter cohort study of patients te...

Measurement of fractionated plasma metanephrines for exclusion of pheochromocytoma: Can specificity be improved by adjustment for age?

BACKGROUND: Biochemical testing for pheochromocytoma by measurement of fractionated plasma metanephrines is limited by false positive rates of up to 18% in people without known genetic predisposition to the disease. The plasma normetanephrine fraction is responsible for most false positives and plasma normetanephrine increases with age. The objective of this study was to determine if we could i...