Diagnostic value of various biochemical parameters for the diagnosis of pheochromocytoma in patients with adrenal mass.
OBJECTIVE
Pheochromocytomas are neoplasms generally characterized by the autonomous production of catecholamines. This study compared various biochemical parameters for the diagnosis of adrenal pheochromocytoma in patients with adrenal mass.


METHODS
One hundred and fifty subjects were studied, including 24 histologically proven pheochromocytomas, 17 aldosterone-secreting and 21 cortisol-secreting adrenal adenomas and 30 nonfunctioning adrenal masses, 16 patients with essential hypertension and 42 healthy normotensive volunteers. Spontaneous blood samples and 24-h urine samples were collected prospectively.


METHODS
Plasma and urinary epinephrine and norepinephrine levels were measured by high performance liquid chromatography, whereas plasma and urinary metanephrine and normetanephrine levels were determined by radioimmunoassay (RIA). Putative ratio thresholds were calculated by receiver operating characteristic (ROC) analysis to balance between sensitivity and specificity.


RESULTS
Plasma normetanephrine was found to be the best single parameter with the highest sensitivity (91.7%) and specificity (95.6%) using a threshold of 126 pg/ml. In combination, plasma normetanephrine and metanephrine had a higher sensitivity of 95.8% with lower specificity (79.4%). All other combinations of plasma and/or urinary parameters demonstrated a lower accuracy.


CONCLUSIONS
Plasma metanephrines measured by RIA are reliable screening parameters for the diagnosis of pheochromocytoma.
Division of Endocrinology, Medical Centre, University of Essen, Germany.
Nicole
N
Unger
Christian
C
Pitt
Ingo Lopez
IL
Schmidt
Martin K
MK
Walz
Kurt W
KW
Schmid
Thomas
T
Philipp
Klaus
K
Mann
Stephan
S
Petersenn
D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000601:surgery / Q000652:urine; D000328:Adult; D015415:Biomarkers; D002395:Catecholamines / Q000097:blood / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D008297:Male; D008676:Metanephrine / Q000652:urine; D008875:Middle Aged; D009647:Normetanephrine / Q000652:urine; D010673:Pheochromocytoma / Q000175:diagnosis* / Q000601:surgery / Q000652:urine; D011446:Prospective Studies; D012372:ROC Curve
D015415:Biomarkers; D002395:Catecholamines; D009647:Normetanephrine; D008676:Metanephrine