Usefulness of bile cytology in the diagnostic management of patients with biliary tract obstruction.

Eighteen patients with evidence of biliary tract obstruction had a total of 29 satisfactory bile samples submitted for diagnostic cytology during a two-year period. These 29 specimens were reviewed in order to determine if bile cytology is useful in the diagnostic management of patients with obstructive biliary tract disease. Twenty-one of the bile specimens were from patients with malignant biliary stricture, and eight were from patients with benign biliary obstruction. Bile cytology was positive for carcinoma in eight samples from patients with malignant stricture and was inconclusive for malignancy in two. There were no false positives. The diagnostic specificity of bile cytology was 100%, the diagnostic sensitivity was 48%, and the diagnostic accuracy was 62%. When carefully collected and promptly processed, bile proved an excellent specimen for cytologic evaluation and was a valuable adjunct to other diagnostic procedures for the detection of carcinoma causing biliary tract obstruction.