title: Plasma normetanephrine and metanephrine for detecting pheochromocytoma in von Hippel-Lindau disease and multiple endocrine neoplasia type 2.
abstract: BACKGROUND
  The detection of pheochromocytomas in patients at risk for these tumors, such as patients with von Hippel-Lindau disease or multiple endocrine neoplasia type 2 (MEN-2), is hindered by the inadequate sensitivity of commonly available biochemical tests. In this study we evaluated measurements of plasma normetanephrine and metanephrine for detecting pheochromocytomas in patients with von Hippel-Lindau disease or MEN-2.
  
  
  METHODS
  We studied 26 patients with von Hippel-Lindau disease and 9 patients with MEN-2 who had histologically verified pheochromocytomas and 50 patients with von Hippel-Lindau disease or MEN-2 who had no radiologic evidence of pheochromocytoma. Von Hippel-Lindau disease and MEN-2 were diagnosed on the basis of germ-line mutations of the appropriate genes. The plasma concentrations of normetanephrine and metanephrine were compared with the plasma concentrations of catecholamines (norepinephrine and epinephrine) and urinary excretion of catecholamines, metanephrines, and vanillylmandelic acid.
  
  
  RESULTS
  The sensitivity of measurements of plasma normetanephrine and metanephrine for the detection of tumors was 97 percent, whereas the other biochemical tests had a sensitivity of only 47 to 74 percent. All patients with MEN-2 had high plasma concentrations of metanephrine, whereas the patients with von Hippel-Lindau disease had almost exclusively high plasma concentrations of only normetanephrine. One patient with von Hippel-Lindau disease had a normal plasma normetanephrine concentration; this patient had a very small adrenal tumor (<1 cm). The high sensitivity of measurements of plasma normetanephrine and metanephrine was accompanied by a high level of specificity (96 percent).
  
  
  CONCLUSIONS
  Measurements of plasma normetanephrine and metanephrine are useful in screening for pheochromocytomas in patients with a familial predisposition to these tumors.
authors.affiliation: Clinical Neuroscience Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1620, USA. ge@box-g.nih.gov
authors.forename: G
authors.initials: G
authors.lastname: Eisenhofer
authors.forename: J W
authors.initials: JW
authors.lastname: Lenders
authors.forename: W M
authors.initials: WM
authors.lastname: Linehan
authors.forename: M M
authors.initials: MM
authors.lastname: Walther
authors.forename: D S
authors.initials: DS
authors.lastname: Goldstein
authors.forename: H R
authors.initials: HR
authors.lastname: Keiser
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004837:Epinephrine / Q000097:blood / Q000652:urine; D005260:Female; D006801:Humans; D008297:Male; D008676:Metanephrine / Q000097:blood* / Q000652:urine; D008875:Middle Aged; D018813:Multiple Endocrine Neoplasia Type 2a / Q000150:complications* / Q000378:metabolism; D009638:Norepinephrine / Q000097:blood / Q000652:urine; D009647:Normetanephrine / Q000097:blood* / Q000652:urine; D010673:Pheochromocytoma / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D012680:Sensitivity and Specificity; D014642:Vanilmandelic Acid / Q000652:urine; D006623:von Hippel-Lindau Disease / Q000150:complications* / Q000378:metabolism
chemical_list: D009647:Normetanephrine; D008676:Metanephrine; D014642:Vanilmandelic Acid; D009638:Norepinephrine; D004837:Epinephrine