title: Imaging features to distinguish malignant and benign branch-duct type intraductal papillary mucinous neoplasms of the pancreas: a meta-analysis.
abstract: OBJECTIVE
  To systematically determine the imaging findings for distinguishing malignant and benign branch-duct type intraductal papillary mucinous neoplasms (BD-IPMNs), including mixed type, and their diagnostic value through meta-analysis of published studies.
  
  
  BACKGROUND
  Management of BD-IPMNs, including mixed type, largely relies on imaging findings. The current knowledge on imaging findings to distinguish malignant and benign BD-IPMNs has weak evidence and is mostly from scattered individual retrospective studies.
  
  
  METHODS
  Thorough literature search in Ovid-MEDLINE and EMBASE databases was conducted to identify studies where findings of computed tomography, magnetic resonance imaging, and endoscopic ultrasonography of BD-IPMNs with or without main pancreatic duct (MPD) dilatation were correlated with surgical/pathological findings. Review of 1128 article candidates, including full-text review of 102 articles, identified 23 eligible articles with a total of 1373 patients for meta-analysis. Dichotomous data regarding distinction between malignant and benign BD-IPMNs were pooled using random effects model to obtain the diagnostic odds ratios (DORs) and their 95% confidence intervals (CIs) of various individual imaging findings for diagnosing malignant BD-IPMN.
  
  
  RESULTS
  Presence of mural nodules revealed the highest pooled DOR (95% CI) of 6.0 (4.1-8.8) followed by MPD dilatation [3.4 (2.3-5.2)], thick septum/wall [unadjusted, 3.3 (1.5-6.9); publication bias-adjusted, 2.3 (0.9-5.5)], and cyst size greater than 3 cm [2.3 (1.5-3.5)]. Multilocularity and multiplicity of the cystic lesions did not reveal statistically significant association with malignancy.
  
  
  CONCLUSIONS
  Presence of mural nodules should be regarded highly suspicious for malignancy warranting a surgical excision whereas cyst size greater than 3 cm, MPD dilatation (5-9 mm), or thick septum/wall may better be managed by careful observation and/or further evaluation.
authors: *Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea †Department of Imaging, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA ‡The Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, MA; and §Department of Radiology, Seoul National University Hospital, Seoul, Korea.
authors: Kyung Won
authors: KW
authors: Kim
authors: Seong Ho
authors: SH
authors: Park
authors: Junhee
authors: J
authors: Pyo
authors: Soon Ho
authors: SH
authors: Yoon
authors: Jae Ho
authors: JH
authors: Byun
authors: Moon-Gyu
authors: MG
authors: Lee
authors: Katherine M
authors: KM
authors: Krajewski
authors: Nikhil H
authors: NH
authors: Ramaiya
mesh_terms: D000368:Aged; D021441:Carcinoma, Pancreatic Ductal / Q000175:diagnosis* / Q000473:pathology; D049448:Cholangiopancreatography, Magnetic Resonance; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography