title: Insulinoma: how reliable is the biochemical evidence?
abstract: METHODS
  We report a case of insulinoma in which the diagnosis was very challenging as some of the biochemical data were consistently equivocal. In order to assess the relative reliability of the analytical tests, retrospective biochemical data on 45 other cases of histologically confirmed insulinoma were evaluated, enabling the most secure diagnostic process to be identified.
  
  
  RESULTS
  The data showed that insulin concentrations alone, although measurable, were equivocal in 17% of cases. The addition of C-peptide values clarified the diagnosis in about 50% of the borderline cases, whilst ketone (beta-hydroxybutyrate) concentrations were low during the prevailing hypoglycaemia in all cases.
  
  
  CONCLUSIONS
  The combination of these three tests is suggested as the most effective method for the biochemical diagnosis of hypoglycaemia due to insulinoma.
authors: The Royal Sussex County Hospital, Eastern Road, Brighton, UK.
authors: N K
authors: NK
authors: Chammas
authors: J D
authors: JD
authors: Teale
authors: J D
authors: JD
authors: Quin
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000097:blood; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000032:analysis; D002096:C-Peptide / Q000097:blood; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000150:complications / Q000175:diagnosis; D007328:Insulin / Q000097:blood; D007340:Insulinoma / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012016:Reference Values; D015203:Reproducibility of Results; D012189:Retrospective Studies
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D020155:3-Hydroxybutyric Acid