Intrahepatic cholangiocarcinoma is a malignant tumor arising from epithelial cells of the intrahepatic bile ducts of grade 2 or higher. Intrahepatic bile duct stones in combination with recurrent purulent cholangitis often lead to intrahepatic bile duct stricture and liver abscess formation. The common infections are bacterial and parasitic. Pathological factors can also contribute to the pathogenesis, such as malnutrition and bacteraemia. Recurrent cholangitis of more than 6 years duration is a high risk factor for the development of cholangiocarcinoma. The incidence is 1.5%-11%. However, bile duct stones combined with bile duct cancer have no special clinical manifestations in the early stage, and are often combined with liver abscesses, which is difficult to diagnose by imaging, resulting in a low early diagnosis rate and posing great difficulties for clinical treatment. In the West, sclerosing cholangitis is the main cause of intrahepatic cholangiocarcinoma; in East Asia, intrahepatic choledocholithiasis is one of the main causes. Intrahepatic bile duct stones mainly occur in East Asia, and in China, they occur mostly in the southeast and coastal areas. With the influx of Asian immigrants, the incidence of intrahepatic bile duct stones in Western countries is also on the rise. The most common cause of intrahepatic bile duct stones is infection, the most common pathogens being bacterial and parasitic infections. The most common bacterial infections are Escherichia coli, and the most common parasites are Schistosoma haematobium and Ascaris lumbricoides. Pathological factors may also contribute to the pathogenesis, such as malnutrition and bacteremia. Recurrent intrahepatic bile duct stones and infections are the most common factors leading to cholangiocarcinoma. Repeated infections, chronic irritation of stones, and bile stasis lead to adenomatous hyperplasia and atypical hyperplasia of the bile duct mucosa, which eventually develop into bile duct cancer. Overseas reports show that bile duct cancer caused by bile duct stones accounts for about 2-10%; domestic reports show that it accounts for 0.36-10%. However, its incidence is related to the region, age, gender, living habits and diagnosis method. The main clinical manifestation of intrahepatic choledocholithiasis is recurrent cholangitis, with repeated high fever and chills. There is no special difference in clinical manifestation between intrahepatic bile duct stones combined with bile duct cancer in early stage and intrahepatic bile duct stones, and the preoperative early diagnosis rate is low. However, the presence of cholangiocarcinoma should be considered if the intrahepatic bile duct stones are of long duration, accompanied by liver abscess formation, recent progressive wasting, intractable pain, uncontrollable infection, and progressively increasing jaundice. Combined cholangiocarcinoma in the advanced stage may show disseminated metastasis in the abdominal cavity, pulmonary metastasis, progressive wasting, jaundice, ascites and other manifestations of malignancy. The diagnosis of intrahepatic bile duct stones combined with cholangiocarcinoma is extremely difficult, and the diagnostic rate of imaging examination is only 0-42%. It is difficult to distinguish from cholangiocarcinoma because of recurrent cholangitis forming abscess, bile tumor and liver lobe atrophy. 4.Serological markers There are no specific serological markers for bile duct stones combined with intrahepatic cholangiocarcinoma. It is not specific for diagnosis. However, combining with imaging can be helpful for diagnosis. CA19C9, CEA and CA-125 are the most commonly used serologic markers for cholangiocarcinoma. CA19C9 is elevated in 85% of bile duct cancers. If CA19C9 is elevated in the presence of obstructive jaundice and remains elevated after the obstruction is removed, it often indicates the presence of cholangiocarcinoma. CEA is elevated in about 30% of cholangiocarcinomas. CA-125 is elevated in 40-50% of cholangiocarcinomas. In addition, some tumor markers such as CA-195, CA-242, DU-PAN-2, IL-6 and trypsinogen-2 may also be altered. 5. Pathological features: intrahepatic bile duct stones combined with bacterial infection, recurrent cholangitis, stones and inflammation form a vicious circle, resulting in bile duct stricture, bile stasis and mechanical irritation may lead to mucosal epithelial hyperplasia and hyperplastic cholangitis. Proliferative cholangitis can lead to atypical epithelial hyperplasia, adenomatous hyperplasia, and subsequent carcinogenesis. Intrahepatic cholangiocarcinoma can also occur in intrahepatic bile ducts that have been operated on without stones. The common pathological types of intrahepatic cholangiocarcinoma include mass formation, peripheral infiltration, and intraluminal growth. The majority of carcinomas occur near stones. All cholangiocarcinomas are adenocarcinomas. Histopathologic features: tumor cells in low columnar, rectangular, vascular, or glandular vesicle shape, with extensive necrosis, infiltration of fibrofatty tissue, invasion of the cell membrane, paracancerous tissue, and chronic cholangitis. The affected bile ducts are narrowed and filled with stones. The treatment of intrahepatic bile duct stones has changed dramatically with the surgeon’s understanding of the disease. The traditional procedure uses bile duct exploration with T-tube drainage. Because of the repeated drainage of intrahepatic stones into the common bile duct, repeated open surgical procedures are performed, and many patients undergo several biliary procedures, with the author having seen patients with up to seven biliary explorations. The patient suffers great physical and psychological damage. In order to solve the recurrent bile duct stones, surgeons have carried out biliary-intestinal anastomosis and subcutaneous intestinal loops, but none of them can fundamentally solve the pathological basis of intrahepatic bile duct stricture and biliary stasis, thus laying the groundwork for bile duct cancer. 7.Conclusion Intrahepatic bile duct stones are one of the main causes of intrahepatic bile duct cancer, but because intrahepatic bile duct stones combined with bile duct cancer have no specific clinical manifestations, repeated inflammatory stimulation, bile duct fibrosis, combined with liver abscess formation, bile tumor formation, imaging is difficult to identify, so the early diagnosis rate is low, and the surgical resection rate is also low. The 5-year survival rate of 5-10% is currently a great challenge for surgeons in both diagnosis and treatment.