title: Adenosquamous carcinoma of the extrahepatic bile duct: clinicopathologic and radiologic features.
abstract: BACKGROUND
  To retrospectively analyze computed tomography (CT) features of adenosquamous carcinoma (ASC) of the extrahepatic bile duct and to correlate them with pathologic findings.
  
  
  METHODS
  Six patients who underwent radical surgical resection for ASC of extrahepatic bile duct were included. CT and pathologic findings were analyzed and correlated with each other.
  
  
  RESULTS
  Five ASCs were periductal infiltrative type and the remaining one was intraductal polypoid type. Histologically, ASC was composed of squamous and glandular components which mixed in an intermingled pattern and was characterized by a high local aggressiveness mainly due to the squamous component. The most common CT findings were a segmental wall thickening with delayed enhancement. Overall, CT features were well correlated with pathologic findings. However, CT tended to underestimate radial extent of the tumor compared with histologic findings.
  
  
  CONCLUSIONS
  Histopathologically, ASC of the extrahepatic bile duct is characterized by greater local aggressiveness. However, their CT findings are not quite different from those of usual adenocarcinoma due to the unique geographic characteristic of being located at a very limited space.
authors.affiliation: Department of Radiology and Institute of Radiation Medicine, Seoul National University Hospital, 28 Yeongon-dong, Jongno-gu, Seoul, 110-744, Korea.
authors.forename: Kyung Won
authors.initials: KW
authors.lastname: Kim
authors.forename: Se Hyung
authors.initials: SH
authors.lastname: Kim
authors.forename: Min A
authors.initials: MA
authors.lastname: Kim
authors.forename: Jeong Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Hee Sun
authors.initials: HS
authors.lastname: Park
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Joon Koo
authors.initials: JK
authors.lastname: Han
authors.forename: Byung Ihn
authors.initials: BI
authors.lastname: Choi
mesh_terms: D000368:Aged; D001650:Bile Duct Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D017734:Bile Ducts, Extrahepatic; D018196:Carcinoma, Adenosquamous / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D002758:Cholangiography; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D016577:Pancreaticoduodenectomy; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed