title: Hepatobiliary cystadenoma exhibiting morphologic changes from simple hepatic cyst shown by 11-year follow up imagings.
abstract: BACKGROUND
  A long-term follow up case of hepatobiliary cystadenoma originating from simple hepatic cyst is rare.
  
  
  METHODS
  We report a case of progressive morphologic changes from simple hepatic cyst to hepatobiliary cystadenoma by 11 - year follow up imaging. A 25-year-old man visited our hospital in 1993 for a simple hepatic cyst. The cyst was located in the left lobe of the liver, was 6 cm in diameter, and did not exhibit calcification, septa or papillary projections. No surgical treatment was performed, although the cyst was observed to gradually enlarge upon subsequent examination. The patient was admitted to our hospital in 2004 due to epigastralgia. Re-examination of the simple hepatic cyst revealed mounting calcification and septa. Abdominal CT on admission revealed a hepatic cyst over 10 cm in diameter and a high-density area within the thickened wall. MRI revealed a mass of low intensity and partly high intensity on a T1-weighted image. Abdominal angiography revealed hypovascular tumor. The serum levels of AST and ALT were elevated slightly, but tumor markers were within normal ranges. Left lobectomy of the liver was performed with diagnosis of hepatobiliary cystadenoma or hepatobiliary cystadenocarcinoma. The resected specimen had a solid component with papillary projections and the cyst was filled with liquid-like muddy bile. Histologically, the inner layer of the cyst was lined with columnar epithelium showing mild grade dysplasia. On the basis of these findings, hepatobiliary cystadenoma was diagnosed.
  
  
  CONCLUSIONS
  We believe this case provides evidence of a simple hepatic cyst gradually changing into hepatobiliary cystadenoma.
authors.affiliation: Department of Surgery, Tokushima Red Cross Hospital, Komatsushima-City, Tokushima Prefecture, Japan. naotowakimachi@hotmail.co.jp
authors.forename: Naoto
authors.initials: N
authors.lastname: Fukunaga
authors.forename: Masashi
authors.initials: M
authors.lastname: Ishikawa
authors.forename: Hisashi
authors.initials: H
authors.lastname: Ishikura
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Ichimori
authors.forename: Suguru
authors.initials: S
authors.lastname: Kimura
authors.forename: Akihiro
authors.initials: A
authors.lastname: Sakata
authors.forename: Koichi
authors.initials: K
authors.lastname: Sato
authors.forename: Jyunichi
authors.initials: J
authors.lastname: Nagata
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Fujii
mesh_terms: D000328:Adult; D001661:Biliary Tract Neoplasms / Q000175:diagnosis / Q000473:pathology*; D002760:Cholangiopancreatography, Endoscopic Retrograde; D003537:Cystadenoma / Q000175:diagnosis / Q000473:pathology*; D003560:Cysts / Q000473:pathology*; D005500:Follow-Up Studies; D006801:Humans; D008107:Liver Diseases / Q000473:pathology*; D008113:Liver Neoplasms / Q000175:diagnosis / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D014057:Tomography, X-Ray Computed