title: Intraductal papillary-mucinous tumors of the pancreas: differential diagnosis between benign and malignant tumors by endoscopic ultrasonography.
abstract: OBJECTIVE
  Recently, intraductal papillary-mucinous tumor (IPMT) of the pancreas has increasingly been recognized. However, differential diagnosis between benign and malignant IPMT is often difficult using conventional imaging modalities. The purpose of this study was to retrospectively investigate the value of endoscopic ultrasonography (EUS) for differentiating malignant from benign IPMT.
  
  
  METHODS
  A total of 51 patients with IPMT were preoperatively examined by EUS. The endosonograhic findings were compared with histopathological findings of the resected specimens.
  
  
  RESULTS
  In main duct type IPMT, the diameter of the main pancreatic duct (MPD) was > or =10 mm in seven of the eight malignant tumors, compared with two of the seven benign tumors (p < 0.05). In branch duct type IPMT, three of the four large tumors (>40 mm) with irregular thick septa were malignant lesions. In both main duct type IPMT and branch duct IPMT, eight patients had large mural nodules (>10 mm); seven of the eight tumors were malignant and one of the eight tumors was benign. When the tumor was diagnosed as malignant according to above three findings, EUS was able to differentiate between malignant and benign IPMT with an accuracy of 86%.
  
  
  CONCLUSIONS
  Main duct type tumors with > or =10 mm dilated MPD, branch duct type tumors (>40 mm) with irregular septa, and large mural nodules (>10 mm) strongly suggest malignancy on EUS. EUS would be a useful modality for differentiating between benign and malignant IPMT.
authors.affiliation: Third Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kubo
authors.forename: Y
authors.initials: Y
authors.lastname: Chijiiwa
authors.forename: K
authors.initials: K
authors.lastname: Akahoshi
authors.forename: S
authors.initials: S
authors.lastname: Hamada
authors.forename: N
authors.initials: N
authors.lastname: Harada
authors.forename: T
authors.initials: T
authors.lastname: Sumii
authors.forename: M
authors.initials: M
authors.lastname: Takashima
authors.forename: H
authors.initials: H
authors.lastname: Nawata
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000000981:diagnostic imaging* / Q000473:pathology; D000231:Adenocarcinoma, Papillary / Q000000981:diagnostic imaging* / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D004724:Endoscopy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000000981:diagnostic imaging / Q000473:pathology; D010183:Pancreatic Ducts / Q000000981:diagnostic imaging / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D014463:Ultrasonography