Cholangiography and bile cytopathology in the diagnosis of biliary tract obstruction.

: Both percutaneous and endoscopic cholangiography identify strictures, stones, and other causes of biliary obstruction. With a radiologic diagnosis, benign and malignant causes of biliary obstruction can often be differentiated, but cholangiography does not provide a pathologic diagnosis. Therefore, we recommend cytologic examination of bile obtained during cholangiography to provide pathologic evidence of malignant causes of bile duct obstruction. We present the results of the diagnostic work-up of 17 patients with biliary obstruction to demonstrate the value of examining bile for malignant cells in all cases of biliary obstruction requiring cholangiography. If bile is cytopathologically normal, the diagnostic work-up must proceed. Abnormal findings on cytologic examination of bile in this study were confirmed with a tissue diagnosis or at operation (once) for malignant neoplasm in 100% of cases (ie, there were no false-positive results).