Biliary brush cytology: factors associated with positive yields on biliary brush cytology

To evaluate the yield of brushing biliary strictures and the factors associated with a positive result in biliary strictures.

Data on all consecutive patients (01/02-10/05) who were identified to have a biliary stricture and who underwent biliary brush cytology were collected. The yield of positive biliary brush cytology was evaluated and compared to results with the gold standard for diagnosis (defined as either definitive surgical histology or clinical course). Additionally, associated factors of positive results including stricture location, gender, age, mass size, length of stricture, and dilatation prior to brushing cytology were assessed.

From 199 patients who had brushing cytology samples (10 patients were excluded due to lack of gold standard diagnosis), 77 patients had positive brushing cytology (yield 41%). Variables associated with positive cytology brushing on initial endoscopic retrograde cholangiography were age 1.02 (1.00-1.05), mass size>1 cm 2.22 (1.01-4.89) and length of stricture>1 cm 3.49 (1.18-10.2). The sensitivity of biliary brushing was 61%, its specificity 98%, the positive predictive value reached 99%, and the negative predictive value was 57%.

Our results revealed a 41% positive yield from brushing cytology. The sensitivity of biliary brushing cytology in our center was 61% and the specificity was 98%. Predictors of positive yield include older age, mass size>1 cm, and stricture length of >1 cm.