title: Computed tomography criteria for discrimination of adrenal adenomas and adrenocortical carcinomas: analysis of the German ACC registry.
abstract: OBJECTIVE
  Thresholds of 2-20 hounsfield units (HU) in unenhanced computed tomography (CT) are suggested to discriminate benign adrenal tumors (BATs) from malignant adrenal tumors. However, these studies included only low numbers of adrenocortical carcinomas (ACCs). This study defines a HU threshold by inclusion of a large cohort of ACCs.
  
  
  METHODS
  Retrospective, blinded, comparative analysis of CT scans from 51 patients with ACCs (30 females, median age 49 years) and 25 patients with BATs (12 females, median age 64 years) diagnosed during the period of 2005-2010 was performed.
  
  
  METHODS
  Tumor density was evaluated in unenhanced CT by two blinded investigators.
  
  
  RESULTS
  Median tumor size was 9 cm (range 2.0-20) for ACCs vs 4 cm (2.0-7.5) for BATs (P<0.0001). In ACCs, the median unenhanced HU value was 34 (range 14-74) in comparison with 5 (-13 to 40) in BATs (P<0.0001). ROC analysis revealed a HU of 21 as threshold with the best diagnostic accuracy (sensitivity 96%, specificity 80%, and AUC 0.89). However, two ACCs that were 5 and 6 cm in size would have been missed. Setting the threshold to 13.9 allowed for 100% sensitivity, but a lower specificity of 68%.
  
  
  CONCLUSIONS
  This first large study on ACCs confirmed that the vast majority of ACCs have unenhanced HU >21. However, to avoid misdiagnosing an ACC as benign, a threshold of 13 should be used.
authors.affiliation: ENDOC Center for Endocrine TumorsAltonaer Street 59, 20357 Hamburg, GermanyDepartment of Internal MedicineUniversity of Hamburg, Hamburg, GermanyPraenobis HamburgHamburg, GermanyDepartment of RadiologyEndocrine and Diabetes UnitDepartment of Internal Medicine I, University HospitalComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, Germany stephan.petersenn@endoc-med.de.
authors.forename: Stephan
authors.initials: S
authors.lastname: Petersenn
authors.affiliation: ENDOC Center for Endocrine TumorsAltonaer Street 59, 20357 Hamburg, GermanyDepartment of Internal MedicineUniversity of Hamburg, Hamburg, GermanyPraenobis HamburgHamburg, GermanyDepartment of RadiologyEndocrine and Diabetes UnitDepartment of Internal Medicine I, University HospitalComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, Germany.
authors.forename: Paul-Ajoy
authors.initials: PA
authors.lastname: Richter
authors.affiliation: ENDOC Center for Endocrine TumorsAltonaer Street 59, 20357 Hamburg, GermanyDepartment of Internal MedicineUniversity of Hamburg, Hamburg, GermanyPraenobis HamburgHamburg, GermanyDepartment of RadiologyEndocrine and Diabetes UnitDepartment of Internal Medicine I, University HospitalComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Broemel
authors.affiliation: ENDOC Center for Endocrine TumorsAltonaer Street 59, 20357 Hamburg, GermanyDepartment of Internal MedicineUniversity of Hamburg, Hamburg, GermanyPraenobis HamburgHamburg, GermanyDepartment of RadiologyEndocrine and Diabetes UnitDepartment of Internal Medicine I, University HospitalComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, Germany.
authors.forename: Christian O
authors.initials: CO
authors.lastname: Ritter
authors.affiliation: ENDOC Center for Endocrine TumorsAltonaer Street 59, 20357 Hamburg, GermanyDepartment of Internal MedicineUniversity of Hamburg, Hamburg, GermanyPraenobis HamburgHamburg, GermanyDepartment of RadiologyEndocrine and Diabetes UnitDepartment of Internal Medicine I, University HospitalComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, Germany.
authors.forename: Timo
authors.initials: T
authors.lastname: Deutschbein
authors.affiliation: ENDOC Center for Endocrine TumorsAltonaer Street 59, 20357 Hamburg, GermanyDepartment of Internal MedicineUniversity of Hamburg, Hamburg, GermanyPraenobis HamburgHamburg, GermanyDepartment of RadiologyEndocrine and Diabetes UnitDepartment of Internal Medicine I, University HospitalComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, Germany.
authors.forename: Frank-Ulrich
authors.initials: FU
authors.lastname: Beil
authors.affiliation: ENDOC Center for Endocrine TumorsAltonaer Street 59, 20357 Hamburg, GermanyDepartment of Internal MedicineUniversity of Hamburg, Hamburg, GermanyPraenobis HamburgHamburg, GermanyDepartment of RadiologyEndocrine and Diabetes UnitDepartment of Internal Medicine I, University HospitalComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, Germany.
authors.forename: Bruno
authors.initials: B
authors.lastname: Allolio
authors.affiliation: ENDOC Center for Endocrine TumorsAltonaer Street 59, 20357 Hamburg, GermanyDepartment of Internal MedicineUniversity of Hamburg, Hamburg, GermanyPraenobis HamburgHamburg, GermanyDepartment of RadiologyEndocrine and Diabetes UnitDepartment of Internal Medicine I, University HospitalComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, Germany ENDOC Center for Endocrine TumorsAltonaer Street 59, 20357 Hamburg, GermanyDepartment of Internal MedicineUniversity of Hamburg, Hamburg, GermanyPraenobis HamburgHamburg, GermanyDepartment of RadiologyEndocrine and Diabetes UnitDepartment of Internal Medicine I, University HospitalComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Fassnacht
mesh_terms: D000293:Adolescent; D000306:Adrenal Cortex Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000473:pathology; D018246:Adrenocortical Adenoma / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000473:pathology; D018268:Adrenocortical Carcinoma / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012042:Registries; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult