title: Adrenocortical tumours: high CT attenuation value correlates with eosinophilia but does not discriminate lipid-poor adenomas from malignancy.
abstract: BACKGROUND
  Characterisation of adrenal tumours is an important clinical problem. Unenhanced CT is the primary imaging modality to assess the nature of these lesions.
  
  
  OBJECTIVE
  To study the correlation between unenhanced CT attenuation value and the specific histopathology, as well as the proportion of lipid-poor eosinophilic cells in adrenocortical tumours.
  
  
  METHODS
  We studied retrospectively primary adrenocortical tumours that had been operated on at Helsinki University Central Hospital between 2002 and 2008. Of 171 tumours, 79 had appropriate preoperative CT scans and were included in the study. We evaluated the unenhanced CT attenuation values (Hounsfield units, HU) of these tumours and determined their histopathological diagnosis by the Weiss scoring system. We also assessed the proportion of lipid-poor eosinophilic cells for each tumour.
  
  
  RESULTS
  Unenhanced CT attenuation value (HU) in adrenocortical tumours correlated well with the proportion of lipid-poor eosinophilic cells (rs=0.750, p<0.001). HU and Weiss score also had a correlation (rs=0.582, p<0.001).
  
  
  CONCLUSIONS
  Unenhanced CT attenuation value correlates well with the percentage of lipid-poor eosinophilic cells, but unenhanced CT attenuation value fails to differentiate between benign lipid-poor adenomas and malignant adrenocortical tumours. All adrenocortical tumours with unenhanced CT attenuation value ≤10 HU are histologically benign lipid-rich tumours.
authors.affiliation: Department of Pathology, Haartman Institute, University of Helsinki and HUSLAB, , Helsinki, Finland.
authors.forename: Mirkka
authors.initials: M
authors.lastname: Pennanen
authors.forename: Merja
authors.initials: M
authors.lastname: Raade
authors.forename: Johanna
authors.initials: J
authors.lastname: Louhimo
authors.forename: Timo
authors.initials: T
authors.lastname: Sane
authors.forename: Ilkka
authors.initials: I
authors.lastname: Heiskanen
authors.forename: Johanna
authors.initials: J
authors.lastname: Arola
authors.forename: Caj
authors.initials: C
authors.lastname: Haglund
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry / Q000175:diagnosis / Q000000981:diagnostic imaging*; D000293:Adolescent; D000306:Adrenal Cortex Neoplasms / Q000737:chemistry / Q000175:diagnosis / Q000000981:diagnostic imaging*; D018246:Adrenocortical Adenoma / Q000737:chemistry / Q000175:diagnosis / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003287:Contrast Media; D003937:Diagnosis, Differential; D004802:Eosinophilia / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008055:Lipids / Q000032:analysis; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D003287:Contrast Media; D008055:Lipids
keywords: Adrenal Gland; Diagnostics; Histopathology; Neoplasms