Brushing Cytology of the Biliary Tract: Bile Juice from the ERCP Sheath Tube Provides Cell-Rich Smear Samples

Abstract

Objectives: To improve the diagnostic accuracy of bile smear cytology, we assessed two cell-yielding procedures. Study Design: One hundred and forty-one patients with biliary stricture underwent endoscopic retrograde cholangiopancreatography (ERCP) and conventional brush sampling. The cytologist cut the brush head off the support wire, centrifuged it directly in tissue culture medium for 1 min at 3,000 rpm, centrifuged the medium again and then smeared the cell pellet onto slides. The remaining sheath tube was then cut into 12-cm segments, which were centrifuged in a centrifuge tube for 1 min at 3,000 rpm, collected and submitted for cytospin preparation. Results: The final histopathological diagnoses based on surgery, biopsy or clinical progression were evaluated for sensitivity, specificity and accuracy. Using conventional smears alone, the sensitivity, specificity and accuracy in patients with biliary stricture were 66.1, 80.7 and 68.8%, respectively. For conventional smears, brush washing and sheath tube contents together, the sensitivity improved to 73.9%, specificity to 100% and accuracy to 78.7%. In the patients with bile duct carcinoma, the sensitivity, specificity and accuracy were 87.3, 100 and 90.7%, respectively. Conclusion: Superior diagnostic accuracy was achieved when conventional smear procedures were combined with the two new procedures.