title: Lessons from an unpleasant surprise: a biochemical strategy for the diagnosis of pheochromocytoma.
abstract: OBJECTIVE
  To audit the performances of the analytes used in the diagnosis of pheochromocytoma and to present a graphical guideline to help the diagnosis.
  
  
  METHODS
  A 5 year retrospective study.
  
  
  METHODS
  Laboratory and departments of a university hospital.
  
  
  METHODS
  In-patients, suspected of bearing a pheochromocytoma, were investigated for urinary metanephrines and catecholamines (photometric method) and vanillylmandelic acid, fractionated catecholamines and metanephrines [high pressure liquid chromatography (HPLC) coupled to electrochemical detection (ED)] urinary excretion.
  
  
  RESULTS
  Patients with a pheochromocytoma (24 out of 2003 patients) were diagnosed by the combination of normetanephrine and metanephrine determination.
  
  
  RESULTS
  All analytes but dopamine were significantly elevated in patients with a pheochromocytoma. The area under the receiver operating characteristics (ROC) curves were the highest for total metanephrines, normetanephrine and metanephrine determinations. Because of analytical interferences in the metanephrines determination, the normetanephrine and metanephrine performed better. It is noteworthy that all pheochromocytomas had either normetanephrine or metanephrine levels above their respective optimal threshold (sensitivity 100%). The best optimal threshold performance was reached by the mean of three daily samples. Total or fractionated catecholamines or vanillylmandelic acid were less accurate tools.
  
  
  CONCLUSIONS
  Amongst urinary tests, the combined use of HPLC/ED determination of normetanephrine and metanephrine seems the most effective screening strategy for the diagnosis of pheochromocytoma. The older total metanephrine photometric assay is grieved by analytical interferences.
authors.affiliation: Department of Nuclear Medicine, Centre Hospitalier Universitaire de Bordeaux, Pessac, France.
authors.forename: V
authors.initials: V
authors.lastname: Gardet
authors.forename: B
authors.initials: B
authors.lastname: Gatta
authors.forename: G
authors.initials: G
authors.lastname: Simonnet
authors.forename: A
authors.initials: A
authors.lastname: Tabarin
authors.forename: G
authors.initials: G
authors.lastname: Chêne
authors.forename: D
authors.initials: D
authors.lastname: Ducassou
authors.forename: J B
authors.initials: JB
authors.lastname: Corcuff
mesh_terms: D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000652:urine*; D000328:Adult; D000368:Aged; D002395:Catecholamines / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D004563:Electrochemistry; D005260:Female; D006801:Humans; D008297:Male; D008676:Metanephrine / Q000652:urine*; D008875:Middle Aged; D009647:Normetanephrine / Q000652:urine*; D010673:Pheochromocytoma / Q000175:diagnosis* / Q000652:urine*; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D014642:Vanilmandelic Acid / Q000652:urine
chemical_list: D002395:Catecholamines; D009647:Normetanephrine; D008676:Metanephrine; D014642:Vanilmandelic Acid