title: The concept of perihilar cholangiocarcinoma is valid.
abstract: BACKGROUND
  The term perihilar cholangiocarcinoma has been used for all tumours involving or requiring resection of the hepatic confluence. However, it does not distinguish between intrahepatic and extrahepatic hilar tumours, and has no clinicopathological basis. This retrospective study examined whether the concept of perihilar cholangiocarcinoma is valid clinically.
  
  
  METHODS
  Some 250 patients with perihilar cholangiocarcinoma were divided into extrahepatic (EHC, 167 patients) and intrahepatic (IHC, 83) groups based on tumour location. Clinicopathological data were compared between these groups.
  
  
  RESULTS
  Liver, portal vein, venous and lymphatic invasion, and nodal metastasis were more common in IHCs than EHCs, whereas histological grade and incidence of perineural invasion were similar. IHCs were more advanced at the time of surgery; stage III or IV disease was found in 37.7 per cent of EHCs and 59 per cent of IHCs. Survival was marginally better for patients with EHCs than for those with IHCs (29.3 versus 20 per cent at 5 years; P = 0.057), but survival rates were similar for each tumour stage in the American Joint Committee on Cancer classification.
  
  
  CONCLUSIONS
  Combining EHC and IHC under the term perihilar cholangiocarcinoma is valid, as these tumours have comparable biological behaviour, with similar clinical management depending on stage and invasion.
authors: Department of Surgery, Division of Surgical Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors: T
authors: T
authors: Ebata
authors: J
authors: J
authors: Kamiya
authors: H
authors: H
authors: Nishio
authors: T
authors: T
authors: Nagasaka
authors: Y
authors: Y
authors: Nimura
authors: M
authors: M
authors: Nagino
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000401:mortality / Q000473:pathology*; D017734:Bile Ducts, Extrahepatic / Q000473:pathology*; D001653:Bile Ducts, Intrahepatic / Q000473:pathology*; D018281:Cholangiocarcinoma / Q000401:mortality / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods / Q000401:mortality; D012189:Retrospective Studies; D055815:Young Adult