title: Natural history of pancreatic intraductal papillary mucinous tumor of branch duct type: follow-up study by magnetic resonance cholangiopancreatography.
abstract: OBJECTIVE
  The purpose of this study was to elucidate the natural history of branch duct type pancreatic intraductal papillary mucinous tumor (IPMT) by evaluating serial changes in the magnetic resonance cholangiopancreatography (MRCP) findings of patients diagnosed with pancreatic IPMT of branch duct type.
  
  
  METHODS
  Thirty-five patients had branch duct type IPMT, including 9 patients with separate lesions, and underwent initial and follow-up MRCP over a period of more than 12 months. The maximum diameter of the cystic lesion, the presence of associated main pancreatic duct (MPD) dilatation, and the presence of a filling defect were evaluated. Serial changes in these findings were analyzed.
  
  
  RESULTS
  Tumor enlargement on follow-up MRCP was observed in 7 cases. Of the 29 branch duct IPMTs without associated MPD dilatation or a filling defect identified on initial MRCP, only 1 showed gradual tumor enlargement. In 4 cases, the cyst size decreased on follow-up MRCP.
  
  
  CONCLUSIONS
  Branch duct type IPMTs grow slowly and can be monitored without operation provided that the tumor shows no associated MPD dilatation or filling defect.
authors.affiliation: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. irie@med.kyushu-u.ac.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Irie
authors.forename: Kengo
authors.initials: K
authors.lastname: Yoshimitsu
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Aibe
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Tajima
authors.forename: Akihiro
authors.initials: A
authors.lastname: Nishie
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Nakayama
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kakihara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Honda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001659:Biliary Tract / Q000473:pathology; D002760:Cholangiopancreatography, Endoscopic Retrograde; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000473:pathology; D010183:Pancreatic Ducts / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000175:diagnosis*