title: Intraductal papillary mucinous neoplasms of the pancreas: differentiation of malignant and benign tumors by endoscopic ultrasound findings of mural nodules.
abstract: OBJECTIVE
  Intraductal papillary mucinous neoplasms (IPMNs)have a wide pathologic spectrum and it is difficult to differentiate malignant from benign tumors. The aim of this study was to identify predictors of malignancy using contrast-enhanced endoscopic ultrasound (CE-EUS).
  
  
  METHODS
  In our institute, main duct type and mixed type IPMNs, branch duct type IPMNs with mural nodules, and IPMNs with coexistent invasive ductal cancer were indications for surgery. Eighty-seven IPMNs (14 main duct, 25 mixed, and 48 branch duct type) were resected and CE-EUS findings were compared with pathologic findings. Twelve clinicopathological variables and CE-EUS morphologic findings were assessed.Mural nodules defined as blood flow supplied protrusions were classified into 4 types: type I: low papillary nodule, type II: polypoid nodule, type III:papillary nodule, and type IV: invasive nodule.
  
  
  RESULTS
  Forty-two, 26, 16, and 3 were pathologically diagnosed as adenoma,noninvasive carcinoma, invasive IPMNs, and coexistent invasive ductal cancer, respectively. Multivariable logistic regression analysis showed that types III/IV mural nodule (odds ratio = 10.8; 95% confidential intervals = 2.75-56.1) and symptomatic IPMNs (odds ratio = 4.31; 95% confidential intervals = 1.37-14.7) were significant for malignancy. For mural nodule diameter, invasive IPMNs were significantly larger, but types III and IV mural nodules were more frequently associated with malignancy, particularly invasive cancer, at 88.9% and 91.7%, respectively. The diagnosis of IPMNs with types III or IV mural nodule as malignant resulted in a sensitivity of 60%, specificity of 92.9%, and accuracy of 75.9%.
  
  
  CONCLUSIONS
  In conclusion, new morphologic criteria were useful to identify the malignant potentials of IPMNs.
authors.affiliation: Department of Gastroenterology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Eizaburo
authors.initials: E
authors.lastname: Ohno
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Hirooka
authors.forename: Akihiro
authors.initials: A
authors.lastname: Itoh
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Ishigami
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Katano
authors.forename: Naoki
authors.initials: N
authors.lastname: Ohmiya
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Niwa
authors.forename: Hidemi
authors.initials: H
authors.lastname: Goto
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D044963:Biopsy, Fine-Needle; D021441:Carcinoma, Pancreatic Ductal / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology*; D015331:Cohort Studies; D016001:Confidence Intervals; D003287:Contrast Media; D003937:Diagnosis, Differential; D019160:Endosonography / Q000379:methods*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016015:Logistic Models; D008297:Male; D009092:Mucous Membrane / Q000000981:diagnostic imaging / Q000473:pathology; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness / Q000473:pathology*; D009367:Neoplasm Staging; D016017:Odds Ratio; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology*; D011336:Probability; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media