title: Distinguishing benign from malignant intraductal papillary mucinous tumors of the pancreas by imaging techniques.
abstract: OBJECTIVE
  It is often difficult to differentiate benign from malignant intraductal papillary mucinous tumors (IPMTs). This study aimed to differentiate them using various imaging techniques.
  
  
  METHODS
  Receiver operating characteristic curves were used to establish optimal cutoff values to differentiate benign from malignant tumors in 121 patients with histologically confirmed IPMTs.
  
  
  RESULTS
  For branch duct type, accuracy for malignancy was highest using endoscopic ultrasonography (EUS) to measure the cyst diameter, and accuracy was 68.2% at a cutoff value of 33.9 mm. For main duct type, accuracy was highest, 71.1% at a cutoff value of 8.4 mm for main duct diameter, with magnetic resonance cholangiopancreatography. For all imaging techniques and findings, accuracy was highest using EUS, 76.4% at a cutoff value of 5.4 mm for height of protrusion. Each imaging technique had a positive predictive value of 80% if the cut off value for the height of the protruding lesion was met.
  
  
  CONCLUSIONS
  Malignancy can be strongly suspected when the height of protrusion exceeds the respective cutoff values. EUS was most effective to differentiate benign IPMTs from malignant tumors by assessing the height of protrusion.
authors.affiliation: Department of Internal Medicine and Clinical Oncology, Chiba University School of Medicine, Chiba, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Baba
authors.forename: Taketo
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ishihara
authors.forename: Akitoshi
authors.initials: A
authors.lastname: Kobayashi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Oshima
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Sakaue
authors.forename: Kazuki
authors.initials: K
authors.lastname: Kato
authors.forename: Masaaki
authors.initials: M
authors.lastname: Ebara
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Saisho
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D000231:Adenocarcinoma, Papillary / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D021441:Carcinoma, Pancreatic Ductal / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D002760:Cholangiopancreatography, Endoscopic Retrograde; D049448:Cholangiopancreatography, Magnetic Resonance; D003952:Diagnostic Imaging / Q000379:methods*; D004724:Endoscopy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D018084:Ultrasonography, Interventional