title: Diagnostic value of serum chromogranin-A combined with MIBG scintigraphy inpatients with adrenal incidentalomas.
abstract: OBJECTIVE
  Adrenal incidentalomas (AI) are defined as asymptomatic adrenal masses occasionally discovered during high-resolution imaging procedures, as computed tomography or magnetic resonance. Pheochromocytoma, a chromaffin tumour, must be excluded before any invasive diagnostic or therapeutic procedure, in order to avoid dangerous acute catecholamines-release into blood stream. Chromogranin-A (CgA) is a member of the granin family contained in secretory vesicles of chromaffin system. This study investigated the performance of serum CgA in detecting or excluding pheochromocytoma among patients with AI.
  
  
  METHODS
  We enrolled 348 patients by AI > 20 mm without clinical or biochemical signs for corticosteroids overproduction. Serum CgA was assayed by a specific immunoradiometric method and a [123I] metaiodobenzylguanidine (MIBG) scan was performed in the 39 CgA-positive patients.
  
  
  RESULTS
  Eighteen out of these patients showed a positive scan and were submitted to laparoscopic adrenalectomy. Pheochromocytoma was histologically confirmed in all cases . The patients with positive serum CgA, were reassessed 1 year later by clinical examination and serum CgA assay. None of patients developed clinical symptoms of chromaffin-tissue hyperactivity , nor showed a serum CgA increase. Serum levels of CgA were significantly higher inpatients with pheochromocytoma than inpatients without (P<0.0001).
  
  
  CONCLUSIONS
  We concluded that serum CgA assay is effective as a single marker to detect or exclude sporadic pheochromocytoma among patients with AI > 20mm. Particularly, a negative serum CgA assay may be used to rule out [123I] MIBG imaging and /or other diagnostic procedures.
authors.affiliation: Department of Nuclear Medicne, Oncology Institute of Southerm Switzerland, Bellinzona, Switzerland. luca.giovanella@eoc.ch
authors.forename: L
authors.initials: L
authors.lastname: Giovanella
authors.forename: L
authors.initials: L
authors.lastname: Ceriani
authors.forename: M
authors.initials: M
authors.lastname: Balerna
authors.forename: F
authors.initials: F
authors.lastname: Keller
authors.forename: M
authors.initials: M
authors.lastname: Taborelli
authors.forename: C
authors.initials: C
authors.lastname: Marone
authors.forename: D
authors.initials: D
authors.lastname: Ferone
mesh_terms: D019797:3-Iodobenzylguanidine; D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D053379:Chromogranin A / Q000097:blood*; D005260:Female; D006801:Humans; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D010673:Pheochromocytoma / Q000175:diagnosis* / Q000000981:diagnostic imaging; D019275:Radiopharmaceuticals; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D014408:Biomarkers, Tumor; D053379:Chromogranin A; D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine