title: Diabetes mellitus as the presenting feature of extrahepatic cholangiocarcinoma in situ: case report and review of literature.
abstract: OBJECTIVE
  To report a case of newly recognized diabetes, manifested by hyperglycemic crisis, as the presenting feature of an extrahepatic cholangiocarcinoma in situ.
  
  
  METHODS
  We summarize the initial clinical manifestations and pertinent laboratory, radiologic, and pathologic findings in a patient with hyperglycemic emergency and a biliary carcinoma in situ. A review of the literature involving cholangiocarcinoma, pancreatic tumors, and diabetes mellitus is also presented.
  
  
  RESULTS
  An 85-year-old woman with no prior history of hyperglycemia presented to the hospital in hyperglycemic crisis, without identifiable precipitants. Further work-up disclosed a tumor in the common bile duct. Pathologic analysis, after pancreatoduodenectomy, demonstrated a carcinoma in situ without extension to nearby structures. Adjacent pancreatic islet cells appeared normal. Screening for all relevant islet cell autoantibodies was negative. After tumor removal, mild hyperglycemia persisted, although without insulin requirements.
  
  
  CONCLUSIONS
  Extrahepatic cholangiocarcinoma and diabetes are not usually associated, and to our knowledge, this is the first reported case of a hyperglycemic emergency with this specific type of tumor. The cause-and-effect relationship between the patient's biliary carcinoma in situ and diabetes obviously cannot be confirmed; however, in the absence of other identifiable conditions, it is reasonable to speculate that some factor (or factors) produced by the tumor had a role in the metabolic decompensation. Such a relationship has been considered by others concerning the well-described association between diabetes and carcinoma of the pancreas, in which the underlying pathophysiologic process seems to be insulin resistance. This unusual case of secondary diabetes emphasizes the importance of considering the precise "cause" of the hyperglycemia when the presentation is atypical, as it was in this older, lean patient without risk factors for diabetes.
authors.affiliation: Department of Internal Medicine, Yale University School of Medicine, New, Haven, Connecticut 06520, USA.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Costa
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Chen
authors.forename: Esmeralda C
authors.initials: EC
authors.lastname: Marginean
authors.forename: Silvio E
authors.initials: SE
authors.lastname: Inzucchi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002278:Carcinoma in Situ / Q000150:complications / Q000601:surgery*; D018281:Cholangiocarcinoma / Q000150:complications / Q000601:surgery*; D003138:Common Bile Duct Neoplasms / Q000150:complications / Q000601:surgery*; D003920:Diabetes Mellitus / Q000209:etiology*; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000209:etiology*; D016577:Pancreaticoduodenectomy; D016896:Treatment Outcome