title: Urine catecholamine levels as diagnostic markers for neuroblastoma in a defined population: implications for ophthalmic practice.
abstract: OBJECTIVE
  although elevated urinary catecholamine levels have been reported in 90-95% of patients with neuroblastoma, more recent studies of pediatric Horner syndrome caused by an underling neuroblastoma have reported normal values at presentation. The purpose of this population-based study is to report the percentage of cases of neuroblastoma with elevated urinary catecholamine levels at presentation and to suggest a recommended work-up for cases of idiopathic pediatric Horner syndrome.
  
  
  METHODS
  the medical records of all pediatric (<19 years) residents of Olmsted County, Minnesota diagnosed with neuroblastoma from 1 January 1969 through 31 December 2008 were retrospectively reviewed.
  
  
  RESULTS
  a total of 14 patients <19 years of age were diagnosed with neuroblastoma as residents of Olmsted County, Minnesota, during the 40-year study period. A total of 10 (71%) of the 14 cases manifested elevated urinary catecholamine metabolites at the initial presentation. Urinary vanillylmandelic acid (VMA) levels were greater than twice the upper limit of normal in eight (57%) of 14 cases, whereas homovanillic acid (HVA) levels were greater than two times the upper limit of normal in 10 (71%) of the 14 cases. Three (75%) of the four cases without significantly elevated urinary VMA or HVA levels were diagnosed with stage IV disease, whereas one (25%) had stage II neuroblastoma.
  
  
  CONCLUSIONS
  urinary catecholamine levels were significantly elevated at presentation in 10 (71%) of the 14 neuroblastoma cases during the 40-year study period, suggesting that greater emphasis be placed on performing a thorough physical examination and obtaining warranted imaging studies in cases of idiopathic pediatric Horner syndrome.
authors.affiliation: Mayo Clinic College of Medicine, Mayo Clinic and Mayo Foundation, Rochester, MN, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Smith
authors.forename: N N
authors.initials: NN
authors.lastname: Diehl
authors.forename: B D
authors.initials: BD
authors.lastname: Smith
authors.forename: B G
authors.initials: BG
authors.lastname: Mohney
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000652:urine; D002395:Catecholamines / Q000652:urine*; D002648:Child; D015331:Cohort Studies; D005260:Female; D006719:Homovanillic Acid / Q000652:urine*; D006801:Humans; D007223:Infant; D008297:Male; D009447:Neuroblastoma / Q000175:diagnosis* / Q000652:urine*; D014642:Vanilmandelic Acid / Q000652:urine*
chemical_list: D015415:Biomarkers; D002395:Catecholamines; D014642:Vanilmandelic Acid; D006719:Homovanillic Acid