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.
Conclusion: 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.