Bile cytology: A new scoring system for improving diagnostic accuracy

Background Benign and malignant cells need to be distinguished in any cytological examination of bile. Here, we report an original scoring system to improve the diagnostic accuracy of bile cytology. Methods The study used 158 bile aspiration samples obtained for cytological examination. Fourteen cytological findings were used to differentiate benign and malignant samples. Statistical significance tests and multivariate analysis were used to determine and quantify significant findings and develop a scoring system. Results Four cytological findings were significant in discriminating between benign and malignant cells: abnormal chromatin, irregularly arranged nuclei, irregularly overlapped nuclei, and irregular cluster margins. Our newly developed scoring system based on these four cytological findings yielded excellent results with a sensitivity of 87%, specificity of 98%, and an odds ratio of 329. Conclusions The use of our new scoring system is expected to contribute to the diagnostic accuracy of cytological evaluations of bile samples.