title: Adrenal incidentaloma: review of 197 patients and report of a drug-related false-positive urinary normetanephrine result.
abstract: OBJECTIVE
  To determine the incidence and importance of functioning tumors among incidentally discovered adrenal masses in the era of laparoscopic surgery.
  
  
  METHODS
  We defined adrenal incidentaloma as a tumor detected during abdominal imaging for adrenal-unrelated reasons, and we reviewed 197 consecutive patients with adrenal incidentaloma diagnosed since we started laparoscopic adrenalectomy.
  
  
  RESULTS
  Incidentaloma was discovered initially in 91 (46%) patients and pheochromocytoma was detected as an incidentaloma in 21 (39%) of 54 patients. One patient, a 21-year-old woman taking mesalamine for ulcerative colitis, had a remarkably elevated urinary normetanephrine level, which resulted in the initial misdiagnosis of a 10-cm right adrenal incidentaloma as a pheochromocytoma. Laparoscopic right adrenalectomy resulted in a pathological diagnosis of ganglioneuroma. A series of urinary normetanephrine measurements were taken in parallel with the mesalamine doses. We found that other patients medicated with mesalamine, without adrenal tumors, had elevated urinary normetanephrine levels, confirming that mesalamine metabolites interfere with urinary normetanephrine measurements.
  
  
  CONCLUSIONS
  It is essential to diagnose the functional potential of adrenal incidentaloma preoperatively, and not to perform laparoscopic adrenalectomy for adrenal incidentaloma without careful evaluation first.
authors.affiliation: Department of Breast and Endocrine Surgery, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ito
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Imai
authors.forename: Toyone
authors.initials: T
authors.lastname: Kikumori
authors.forename: Arihiro
authors.initials: A
authors.lastname: Shibata
authors.forename: Takao
authors.initials: T
authors.lastname: Horiba
authors.forename: Hironobu
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Masataka
authors.initials: M
authors.lastname: Sawaki
authors.forename: Reiko
authors.initials: R
authors.lastname: Watanabe
authors.forename: Akimasa
authors.initials: A
authors.lastname: Nakao
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kiuchi
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000601:surgery / Q000652:urine*; D000315:Adrenalectomy / Q000379:methods; D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000493:pharmacokinetics / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000652:urine*; D003093:Colitis, Ulcerative / Q000188:drug therapy / Q000652:urine; D003937:Diagnosis, Differential; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D015994:Incidence; D010535:Laparoscopy; D008297:Male; D019804:Mesalamine / Q000493:pharmacokinetics* / Q000627:therapeutic use; D009647:Normetanephrine / Q000652:urine*; D010673:Pheochromocytoma / Q000175:diagnosis* / Q000601:surgery / Q000652:urine*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D014408:Biomarkers, Tumor; D009647:Normetanephrine; D019804:Mesalamine