title: Intraductal papillary mucinous tumors of the pancreas: thin-section helical CT findings.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the thin-section helical CT findings of intraductal papillary mucinous tumors and to investigate whether helical CT could distinguish between malignant and benign intraductal papillary mucinous tumors.
  
  
  METHODS
  Twenty-seven patients (nine with malignant and 18 with benign intraductal papillary-mucinous tumors) underwent thin-section (3- or 5-mm) helical CT. Two-phase enhanced CT was started 30 and 60-70 sec after injection of contrast material at 3 ml/sec.
  
  
  RESULTS
  In six patients (22.2%), a bulging papilla was depicted on CT. Twenty-five patients (92.6%) had a dilated main pancreatic duct. Cystic lesions were seen in 25 patients (92.6%). Thirteen lesions (48%) were located in the uncinate process, seven (25.9%) were in the head, two (7.4%) were in the body, and three (11%) were in the tail. The cystic lesion was unilocular in five patients (18.5%) and multilocular with a lobulated margin in 20 patients (74%). Communication between the main pancreatic duct and the cystic lesion was depicted in 19 patients (70.4%). The papillary projections corresponding to 3-mm or larger papillary neoplasms were depicted in five patients (18.5%). The bulging papilla was more often observed in malignant than in benign intraductal papillary mucinous tumors (p < 0.05). The caliber of the main pancreatic duct was significantly larger in patients with malignant intraductal papillary mucinous tumors (p > 0.001).
  
  
  CONCLUSIONS
  The most frequently found feature of intraductal papillary mucinous tumors was a lobulated multilocular cystic lesion located in the uncinate process and in contiguity with the dilated main pancreatic duct. In some patients, a bulging papilla and papillary projections in the ducts, which were specific findings, were visualized on CT. The bulging papilla and the caliber of the main pancreatic duct helped differentiate malignant from benign intraductal papillary mucinous tumors.
authors.affiliation: Department of Radiology, Faculty of Medicine, Kagoshima University, Kagoshima City, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Fukukura
authors.forename: F
authors.initials: F
authors.lastname: Fujiyoshi
authors.forename: M
authors.initials: M
authors.lastname: Sasaki
authors.forename: H
authors.initials: H
authors.lastname: Inoue
authors.forename: S
authors.initials: S
authors.lastname: Yonezawa
authors.forename: M
authors.initials: M
authors.lastname: Nakajo
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*