Diagnosis of biliary tract lesions by histological sectioning of brush bristles as alternative to cytological smearing

AIM: To increase the diagnostic potential of endoscopic biliary tract brushing, we devised an approach alternative to cytological smearing, leading to the preoperative histological examination of the collected material. METHODS: One hundred twelve consecutive biliary brush specimens were included. All patients presented a stricture of the biliary tract, leading to a diagnostic procedure by brushing. Immediately following brushing, the endoscopist immersed the brush into methanol and sent it to the pathology laboratory. The brush was introduced into a cassette for paraffin embedding and sections parallel to the long axis of brush were cut until the metal wire was almost reached, then the block was rotated and new sections were obtained from the opposite side. Samples of the mucosa, inflammatory cell aggregates, small fragments of carcinomas, or isolated cells were observed, and displayed an optimal fixation, allowing a definite diagnosis that proved mandatory for therapy in the vast majority of cases (99.1%). RESULTS: The results obtained in 112 consecutive cases using such technique compared with final histological diagnosis proved: 91% sensitivity, 100% specificity, 100% positive predictive value (PPV), and 87% negative predictive value (NPV) (P < 0.001). In nonoperated patients, the clinical diagnosis after at least 6 months of follow-up showed: 95.5% sensitivity, 100% specificity, 100% PPV, and 88.2% NPV (P < 0.001). CONCLUSION: Such novel approach to the preoperative diagnosis of biliary tract lesions proved to be highly sensitive and specific, limiting the inadequate preoperative diagnoses to less than 1%.