title: Cholangiocarcinoma: expanding the spectrum of risk factors.
abstract: BACKGROUND
  Cholangiocarcinoma (CCA) is an epithelial cancer originating from the bile ducts with features of cholangiocyte differentiation. The global incidence of this rare disease is on the rise, and it is the second most common primary hepatobiliary malignancy. We reviewed risk factors for cholangiocarcinoma development and also described potential screening strategies for this malignancy. We also report two cases in which CCA developed in patients without previously determined risk factors known for CCA.
  
  
  CONCLUSIONS
  The first case is a patient with longstanding secondary sclerosing cholangitis (SSC), and the second is a patient with autoimmune hepatitis (AIH). These two cases may indicate a possible association between SSC and AIH with CCA, thus, expanding the spectrum of risk factors of CCA.
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, W19A, 200 First Street, SW, Rochester, MN 55905, USA.
authors.forename: Diaa H
authors.initials: DH
authors.lastname: Elfaki
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Gossard
authors.forename: Keith D
authors.initials: KD
authors.lastname: Lindor
mesh_terms: D000368:Aged; D001650:Bile Duct Neoplasms / Q000209:etiology*; D001653:Bile Ducts, Intrahepatic; D018281:Cholangiocarcinoma / Q000209:etiology*; D015209:Cholangitis, Sclerosing / Q000150:complications*; D005260:Female; D019693:Hepatitis, Autoimmune / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors