title: Ex vivo application of endocytoscopy for determining the longitudinal extent of bile duct cancer: a pathological analysis of 28 resected cases.
abstract: BACKGROUND
  The aim was to examine the diagnostic ability of an endocytoscope system (ECS) for detecting the longitudinal extent of bile duct cancer.
  
  
  METHODS
  We observed the surfaces of the bile duct of 28 consecutive patients undergoing biliary surgery both directly and under methylene blue staining by using an ECS. Based on the change in the microvascular caliber, abnormal vascularity, structural atypia, and cellular atypia, we created an ECS score.
  
  
  RESULTS
  The ECS score produced a median value of 1 (range 0-3) point in normal bile ducts, 3 (0-6) points in cholangitis, 9 (1-10) points in carcinoma in situ (CIS), and 8 (3-11) points in invasive cancer. A significant difference in the scores between cancerous and non-cancerous lesions was found (P < 0.001). The ECS score was able to distinguish non-cancerous lesions from cancerous lesions using the cut-off value of a score less than 5, the accuracy being 92.1%, with a sensitivity of 91.1% and specificity of 93.5%.
  
  
  CONCLUSIONS
  With ECS observation of bile duct specimens, the newly created ECS score was able to clearly distinguish non-cancerous lesions from cancerous lesions. This ECS score method should be validated in the differentiation of various BilIN lesions in the future.
authors.affiliation: Department of Gastroenterological Surgery, Hirosaki University Graduate School of Medicine, Zaifu-cho 5, Hirosaki, Amori, 036-8562, Japan. hakamada@cc.hirosaki-u.ac.jp.
authors.forename: Toru
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Kenichi
authors.initials: K
authors.lastname: Hakamada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ogasawara
authors.forename: Norihisa
authors.initials: N
authors.lastname: Kimura
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kudo
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Sakamoto
authors.forename: Keinosuke
authors.initials: K
authors.lastname: Ishido
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Toyoki
authors.forename: Satoko
authors.initials: S
authors.lastname: Morohashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kijima
mesh_terms: D001650:Bile Duct Neoplasms / Q000473:pathology*; D001652:Bile Ducts / Q000473:pathology*; D003937:Diagnosis, Differential; D016145:Endoscopy, Digestive System / Q000379:methods*; D006801:Humans; D009367:Neoplasm Staging / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies
keywords: Bile duct cancer; Cholangiocarcinoma; Endocytoscopy; Endomicroscopy