title: Intraductal papillary mucinous neoplasms of the pancreas: radiological predictors of malignant transformation and the introduction of bile duct dilation to current guidelines.
abstract: OBJECTIVE
  To evaluate the current guidelines as a model to predict malignancy and to determine further radiological predictors of malignancy in intraductal papillary mucinous neoplasms (IPMNs).
  
  
  METHODS
  384 patients who had undergone a pancreatic operation with the pathological diagnosis of IPMN as well as applicable pre-operative imaging (CT/MRI) were included in the study. Images were evaluated retrospectively in consensus by two radiologists, using a standardized checklist. Descriptive statistics, binary logistic regression and receiver operator curve analysis were performed to assess the International Consensus Guidelines and other radiological predictors of clinical malignancy (defined as carcinoma in situ and invasive carcinoma).
  
  
  RESULTS
  The best independent predictors of malignancy (n = 191) were solid components [odds ratio (OR) 3.98], parenchymal atrophy with main pancreatic duct dilation 5-9 mm (OR: 5.1) and common bile duct (CBD) dilation (OR: 31.26). >96% of all cases with CBD dilation were malignant IPMNs (positive-predictive value 96.4%; negative-predictive value 63.1%). Analysis of the current guidelines showed a diagnostic improvement with the addition of CBD dilation on determining the malignancy of IPMNs (sensitivity 82.2%/86.9%; specificity 72.7%/74.6%). Subanalysis of branch duct intraductal papillary mucinous neoplasms (BD-IPMNs; n = 168) also resulted in a diagnostic improvement with the addition of CBD dilation (sensitivity 28.6%/45.2%; specificity 92.9%/92.1%). The best independent predictors of malignancy for BD-IPMNs were parenchymal atrophy (OR: 4.00) and CBD dilation (OR: 29.3). Frequency analysis revealed that even small BD-IPMNs had already undergone malignant transformation (≤1 cm: 15%; 1-2 cm: 26%; 2-3 cm: 20%) with about 10% of those having a dilated bile duct.
  
  
  CONCLUSIONS
  CBD dilation was a significant positive predictor of malignancy in IPMNs regardless of their size.
  
  
  CONCLUSIONS
  Introduction of CBD dilation as a radiological predictor for malignancy might increase the diagnostic accuracy of current imaging-based guidelines.
authors.affiliation: 1 Radiology Department, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Albert
authors.initials: A
authors.lastname: Strauss
authors.affiliation: 1 Radiology Department, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Matthew
authors.initials: M
authors.lastname: Birdsey
authors.affiliation: 2 Surgery Department, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Fritz
authors.affiliation: 1 Radiology Department, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Bogata D
authors.initials: BD
authors.lastname: Schwarz-Bundy
authors.affiliation: 3 Institute of Pathology Heidelberg, University Hospital of Heidelberg, Heidelberg, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Bergmann
authors.affiliation: 2 Surgery Department, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Thilo
authors.initials: T
authors.lastname: Hackert
authors.affiliation: 1 Radiology Department, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Hans-Ullrich
authors.initials: HU
authors.lastname: Kauczor
authors.affiliation: 4 Diagnostic Imaging Center, Diagnostik Muenchen, München, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Grenacher
authors.affiliation: 1 Radiology Department, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Miriam
authors.initials: M
authors.lastname: Klauss
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000000981:diagnostic imaging* / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001652:Bile Ducts / Q000473:pathology*; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D002758:Cholangiography; D049448:Cholangiopancreatography, Magnetic Resonance; D003251:Constriction, Pathologic; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010179:Pancreas / Q000000981:diagnostic imaging / Q000473:pathology; D010183:Pancreatic Ducts / Q000000981:diagnostic imaging / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed