ABSTRACT
Cholangiocarcinoma is a malignant tumor originating from bile duct epithelium, with insidious onset and high degree of malignancy. Most of the patients were diagnosed at the middle and late stages and the survival rate is very poor. The etiology of cholangiocarcinoma is still unknown. Billary intraepithelial neoplasia, intraductal papillary neoplasm of the bile duct, biliary mucinous cystic neoplasm and intraductal tubular/tubulopapillary neoplasm of the bile duct are considered as precancerous lesions of cholangiocarcinoma. Improving the understanding of precancerous lesions of cholangiocarcinoma, and early treatment of these lesions are important for enhancingthe patients’ quality of life. However, the current understanding of precancerous lesions of cholangiocarcinoma is limited. Development of molecular diagnostic technology is deeply needed. And sensitive and specific biomarkers are urgently needed for the early diagnosis of the high-risk persons accurately, so as to achieve " early detection, early diagnosis and early treatment" . This article reviews how to recognize and deal with precancerous lesions of cholangiocarcinoma.