Brush cytology of the biliary tract: retrospective study of 278 cases with histopathologic correlation.

Bile aspiration during endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangiography has been used as a diagnostic tool in the evaluations of pancreatic and biliary tree strictures for the last two decades. However, recently biliary tract brush cytology has become the method of choice in evaluating pancreatic/biliary tract abnormalities. The aim of this study was to evaluate the accuracy of pancreatobiliary lesions by an endobiliary cytotechnique. From 1993-1999, 278 pancreatobiliary brushings were performed at our institutions. Cytologic material was air-dried for Diff-Quik stain or fixed in ethanol for Papanicolaou staining. The cytologic diagnoses were classified in three categories: 1) benign, 2) atypical/suspicious, or 3) malignant. Subsequent surgical biopsy was available in 87 (31%) patients. There were 150 males and 128 females with a mean age of 63 yr (range 22-97); 167 (60%) were benign cases. Follow-up surgical material was available in 39 cases, seven of which showed adenocarcinoma; 67 of all cases (24%) were atypical/suspicious cases. Follow-up surgical material was available in 31 cases, 17 (55%) of which showed adenocarcinoma; 32 cases (12%) were malignant cases. Follow-up surgical material was available in 15 cases. All 15 cases were in agreement with the cytologic diagnosis. Twelve (4%) cases were unsatisfactory for cytologic examination. Follow-up surgical material was available in two cases. One case showed mucinous cystadenoma of the pancreas. The other case showed benign duct epithelium. Our study shows a sensitivity of 68% and a specificity of 100%. Of the atypical cases, 55% were malignant on follow-up biopsy. Brush cytology of pancreatobiliary strictures is the most widely used technique in the diagnosis of carcinoma, with a high degree of specificity.