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


METHODS
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.


RESULTS
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%.


CONCLUSIONS
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.
Václavík
Jan
J
Department of Internal Medicine, Sternberk Hospital, Sternberk, Czech Republic. vaclavik.j@centrum.cz
Stejskal
David
D
Lacnák
Borek
B
Lazárová
Marie
M
Jedelský
Libor
L
Kadalová
Lenka
L
Janosová
Marie
M
Frysák
Zdenek
Z
Vlcek
Petr
P
D000310:Adrenal Gland Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D019540:Area Under Curve; D003430:Cross-Sectional Studies; D018153:Czech Republic / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008676:Metanephrine / Q000097:blood*; D008875:Middle Aged; D009647:Normetanephrine / Q000097:blood*; D010673:Pheochromocytoma / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D011237:Predictive Value of Tests
D009647:Normetanephrine; D008676:Metanephrine