Diagnostic accuracy of brush cytology with direct smear and cell-block techniques according to preparation order and tumor characteristics in biliary strictures

Abstract

BACKGROUND/AIMS: There are few data supporting the diagnostic yield of brush cytology depending on the order of cytologic preparation method or the location or shape of tumors in biliary strictures. We investigated diagnostic yields and variations in brush cytology with direct smear and cell-block preparations according to sampling preparation sequence and tumor location and shape in biliary strictures. METHODS: Patients who had undergone ERCP with tissue sampling between August 2009 and April 2013 were analyzed retrospectively. Group A was examined using brush cytology with direct smear followed by cell-block with or without biopsy, while the reverse order was performed for group B. RESULTS: Among 138 enrolled patients, 92 patients (A: 36, B: 56) underwent both brush cytology with direct smear and cell-block preparations. No differences in sensitivity, specificity, or accuracy were observed according to the sampling preparation method and the location or shape of tumors in biliary strictures. The cellularity observed from brush cytology with direct smear was better than that from cell-block according to the location of the tumor (p<0.01). The diagnostic yield was increased in both groups with addition of an endobiliary biopsy. CONCLUSIONS: No difference in diagnostic accuracy was observed between the sequences of preparation for brush cytology with direct smear and cell-block techniques. Brush cytology showed better cellularity for diagnosis.