Elevated CA 19-9 levels in a patient with Mirizzi syndrome: case report.

CA 19-9 is a marker of malignancy of the pancreas and biliary tract. We report the case of a patient who had significantly elevated serum CA 19-9 levels and imaging studies suggestive of malignancy. On laparotomy, the patient was found to have Mirizzi syndrome, an uncommon cause of biliary obstruction from an impacted gallstone. This case illustrates that elevated serum CA 19-9 levels must be interpreted cautiously in cases of biliary obstruction.