title: Endocrine pancreatic tumours and helical CT: contrast enhancement is correlated with microvascular density, histoprognostic factors and survival.
abstract: OBJECTIVE
  To assess the role of contrast-enhanced helical CT in the evaluation of tumour vascularity in endocrine pancreatic tumours (EPTs), and to determine the predictive factors of malignancy of EPTs at helical CT with CT-histopathological correlation.
  
  
  METHODS
  Thirty-seven consecutive patients with histopathologically proven EPTs underwent dual-phase helical CT. For each tumour detected, its density relative to the surrounding parenchyma was scored on the pancreatic phase using a 5-point scale. Radiological findings were correlated with histopathological (vessel density count) and clinical follow-up findings.
  
  
  RESULTS
  Thirty of 37 patients had non-functioning EPTs and overall 44 tumours were detected by helical CT (mean size 38, range 5-100 mm). CT showed calcifications in 10 tumours. Calcifications were associated with well-differentiated carcinomas (90%, p = 0.02). Vascular density assessed by light microscopy was significantly correlated with tumour enhancement at the pancreatic phase (p = 0.0001). Poorly differentiated carcinomas were less vascularised than well-differentiated tumours and carcinomas (34 vs. 264 vessels/mm2, p = 0.0073). Tumour differentiation also correlated with tumour enhancement at the pancreatic phase (p = 0.0044, trend test): poorly differentiated carcinomas were hypoattenuating (71%) and isoattenuating or weakly hyperattenuating (29%), compared with well-differentiated carcinomas and tumours that were mainly moderately or strongly hyperattenuating (53%). In univariate analysis, poor tumoral differentiation, hepatic metastasis, high mitotic index, poor tumoral enhancement at the pancreatic phase and less vascularised tumours were correlated with decreased survival rate.
  
  
  CONCLUSIONS
  Enhancement of EPT at CT is correlated with tumour vascularity assessed by light microscopy. Low-enhancing EPT at CT are correlated with poorly differentiated EPT and with a decrease in overall survival.
authors.affiliation: Department of Radiology, Hôpital Beaujon, Clichy, France. mathieurodallec@hotmail.com
authors.forename: M
authors.initials: M
authors.lastname: Rodallec
authors.forename: V
authors.initials: V
authors.lastname: Vilgrain
authors.forename: A
authors.initials: A
authors.lastname: Couvelard
authors.forename: P
authors.initials: P
authors.lastname: Rufat
authors.forename: D
authors.initials: D
authors.lastname: O'Toole
authors.forename: V
authors.initials: V
authors.lastname: Barrau
authors.forename: A
authors.initials: A
authors.lastname: Sauvanet
authors.forename: P
authors.initials: P
authors.lastname: Ruszniewski
authors.forename: Y
authors.initials: Y
authors.lastname: Menu
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007515:Islets of Langerhans / Q000473:pathology; D008297:Male; D008833:Microcirculation / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology*; D011379:Prognosis; D012039:Regional Blood Flow / Q000502:physiology; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed