title: Ileal carcinoid tumors stimulating Crohn's disease: incidence among 176 consecutive cases of ileal carcinoid.
abstract: OBJECTIVE
  There are seven published cases of ileal carcinoid tumor misdiagnosed and treated as Crohn's disease. We evaluated 176 consecutive ileal carcinoid patients to determine the frequency with which this occurs. Clinical, hormonal, and radiographic data of those patients misdiagnosed were also analyzed to determine whether there were clinical lessons to be learned.
  
  
  METHODS
  Records of 176 patients with ileal carcinoid tumors were retrospectively reviewed. It was determined whether patients were diagnosed and treated for Crohn's before the diagnosis of carcinoid was established. Radiographic, hormonal, and clinical data were reviewed and comparison was made to those who were correctly diagnosed as having carcinoid.
  
  
  RESULTS
  Of 176 ileal carcinoid patients, 4 were initially diagnosed and treated as having Crohn's; their mean age was 51.5 +/- 8.9 yr. The hormonal data of patients treated as Crohn's was indistinguishable from patients with known carcinoid. Two of four patients had colonoscopy performed, neither had terminal ileal intubation. None responded to medical therapy and all required surgery for diagnosis. The mean time from symptom onset to the establishment of the correct diagnosis was 24 +/- 6.9 months with a range of 6 to 45 months.
  
  
  CONCLUSIONS
  Although rare, ileal carcinoid tumors may be misdiagnosed as Crohn's disease. In our study approximately 2.3% of patients with ileal carcinoid were initially diagnosed and treated as having Crohn's disease. The presence of disease refractory to medical therapy should alert clinicians to this possibility and urinary 5-HIAA levels should be obtained as a screening test.
authors.affiliation: Department of Medicine, Hospital of the University of Pennsylvania, University of Pennsylvania School of Medicine, Philadelphia 19104-4283, USA.
authors.forename: E Y
authors.initials: EY
authors.lastname: Hsu
authors.forename: J M
authors.initials: JM
authors.lastname: Feldman
authors.forename: G R
authors.initials: GR
authors.lastname: Lichtenstein
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002276:Carcinoid Tumor / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism; D003424:Crohn Disease / Q000175:diagnosis* / Q000378:metabolism; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000652:urine; D007078:Ileal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012701:Serotonin / Q000032:analysis; D013997:Time Factors
chemical_list: D012701:Serotonin; D006897:Hydroxyindoleacetic Acid