Free plasma metanephrines as a screening test for pheochromocytoma in low-risk patients

Publisher Website
Google Scholar
Abstract
Detection of free plasma metanephrines seems to be the most exact method for biochemical diagnosis of pheochromocytoma, but their diagnostic efficacy in the common low-risk clinical settings is debated. A cross-sectional multicentre study including 1260 subjects assessed the diagnostic efficacy of free plasma metanephrine and normetanephrine in low-risk patients screened for resistant or markedly accelerated hypertension, paroxysmal hypertension, 'flushes' and, in a small proportion, for adrenal incidentaloma or genetic predisposition to pheochromocytoma. Pheochromocytoma was identified and verified by histology in 25 subjects (2%), with the diagnosis not confirmed by long-term follow-up or use of imaging techniques in the remaining 1235 individuals. The combined assay of free plasma metanephrines was a highly sensitive (100%) and specific (96.7%) measure, yielding a negative predictive value of 100%. The satisfactory diagnostic efficacy of free plasma metanephrines allows their use as a single screening test in cases of suspected pheochromocytoma in the population with a low pretest probability.