Figure legend:Proposed algorithm of surveillance and treatment for the patients with intrahepatic lithiasis (IHL) (based on the high risk of intrahepatic cholangiocarcinoma (ICC) in IHL). We recommend the nomogram including the risk factors (age, abdominal pain, vomiting, comprehensive imagological diagnosis, ALK, CEA, and CA 19-9) for assessing the probability of ICC. For IHL patients with acute cholangitis, they should be treated for cholangitis firstly, because the result of imaging and serum CA 19-9 for predicting ICC are not accurate in the state of acute cholangitis. The patients with IHL are divided into three groups according to the nomogram. For low risk group (probability of ICC <0.02, total points <100), they are required to receive continuous observation. Liver imaging, liver function, CEA and CA 19-9 need to be checked every one-two years. For medium risk group (probability of ICC 0.02-0.3, total points 100-170), they should be referred for further imaging examination, e.g. enhanced CT, enhanced MRI, PET-CT. Both of the low risk group and median risk group should be valued again through the nomogram after the further examination. For high risk group (probability of ICC >0.3, total points >170), we recommend surgical resection according to the situation of the mass and liver function.
Abbreviations: IHL, intrahepatic lithiasis; ICC, intrahepatic cholangiocarcinoma; PTCD, percuteneous transhepatic cholangio drainage; POCS, peroral cholangioscopy; PTCS, percutaneous transhepatic cholangioscopy; CA 19-9, cancer antigen 19-9; CEA, carcinoembryonic antigen.
