Evaluation of Endoscopic Transpapillary Brushing Cytology for the Diagnosis of Bile Duct Cancer Based on the Histopathologic Findings

Diagnosis of the bile duct cancer still needs more accuracy. Studies on endoscopic retrograde cholangiopancreatography (ERCP)-guided brushing cytology were carried to evaluate the role of the endoscopic transpapillary brushing cytology for the diagnosis of bile duct cancer.The study involved 76 consecutive patients who underwent ERCP-guided bile duct cytology for the diagnosis of bile duct cancer from 2008 to August 2012. Three types of cytological specimens were obtained using different sampling methods, i.e., bile aspiration cytology (BAC), brush tip cytology (BTC), and post brushing bile cytology (PBC), to investigate their diagnostic abilities, and comparatively studied with each macroscopic type of the surgically resected specimens.The cancer-positive rate was 67.1 % (BAC alone: 41.9 %), and the use of BTC and PBC in addition to BAC yielded a statistically significant increase of the cancer-positive rate (p = 0.0031). In 34 resected cases, the cancer-positive rate in relation to the macroscopic type was improved by the addition of BTC and PBC to BAC alone for the papillary (87.5 vs. 40.0 %, p = 0.071) and nodular (100 vs. 70.0 %, p = 0.0603) types, but not for the flat type (62.5 vs. 57.1 %; p = 0.7651).The diagnostic ability of ERCP-guided brushing cytology could be improved by the addition of PBC. However, the cancer-positive rate was the lowest for the flat type of bile duct cancer.