title: Pancreatic cancer: correlation of MR findings, clinical features, and tumor grade.
abstract: OBJECTIVE
  To assess the frequency of occurrence of poorly-marginated and focally-defined pancreatic ductal adenocarcinoma by MRI and to determine whether these appearances correlate with clinical features and histopathological grade.
  
  
  METHODS
  Institutional review board with waiver of informed consent was obtained for this HIPAA compliant study. A total of 33 patients (16 female, 17 male, mean age = 63.5 +/- 12.8, ranging from 41 to 80 years) with histopathologically-proven pancreatic ductal adenocarcinoma who underwent MR examination between August 2000 and February 2005 were retrospectively evaluated. Clinical data and histopathological tumoral grade were obtained from clinical charts; nine of 33 patients were excluded of the histopathological evaluation since their diagnosis was performed by fine needle aspiration biopsy and it was not possible to obtain the histopathological grade. Two radiologists reviewed all cases independently to identify whether cancers were poorly-marginated or focally-defined. Agreement between radiologists was assessed using the kappa coefficient. The overall correlation between imaging findings, clinical features, and histopathological grade was assessed with contingency tables using the Fisher's exact test.
  
  
  RESULTS
  Of the 33 patients, nine (27.2%) were classified as poorly-marginated and 24 (72.8%) as focally-defined. Agreement between the two reviewers was excellent (k = 0.92, 95% confidence interval (CI) = 0.78-1.0). Poorly-marginated cancers exhibited well- to moderately-differentiated histopathology in 71.4% of cases, while focally-defined cancers had well- to moderately-differentiated histopathology in 17.6% of cases, P = 0.02.
  
  
  CONCLUSIONS
  A poorly-marginated appearance of pancreatic ductal carcinoma on MRI is not uncommon. These cancers exhibited statistically significant moderate- to well-differentiated histopathology compared to focally-defined cancers.
authors.affiliation: Department of Radiology, University of North Carolina, Chapel Hill, North Carolina 27599-7510, USA.
authors.forename: Jorge
authors.initials: J
authors.lastname: Elias
authors.forename: Richard C
authors.initials: RC
authors.lastname: Semelka
authors.forename: Ersan
authors.initials: E
authors.lastname: Altun
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Tsurusaki
authors.forename: Ertan
authors.initials: E
authors.lastname: Pamuklar
authors.forename: Mauricio
authors.initials: M
authors.lastname: Zapparoli
authors.forename: Vasileios
authors.initials: V
authors.lastname: Voultsinos
authors.forename: Diane M
authors.initials: DM
authors.lastname: Armao
authors.forename: Tara
authors.initials: T
authors.lastname: Rubinas
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000473:pathology*; D018709:Statistics, Nonparametric