ObjectiveTo discuss the CT characteristics of combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-CC), and analyze the reasons for its misdiagnosis. MethodWe retrospectively analyzed the CT data of 7 patients diagnosed to have combined hepatocellular carcinoma and cholangiocarcinoma by postoperative pathological analysis between January 2009 and February 2015. We analyzed such characteristics as location, shape, density, enhanced features, surrounding invasion, mediastinal lymph node metastasis, cirrhosis and pyoperitoneum of the disease. ResultsThere were 7 tumors among the 7 patients. Plain scan showed slightly lower density nodules or masses. After the enhancement of arterial phase, 5 tumors showed obvious inhomogeneous enhancement but 2 mild marginal enhancement. During the portal venous phase and the delay stage, the regional degree of tumor foci was significantly decreased, but some regions sustained annular or nodular and patchy enhancement. Among the 7 cases, the portal vein was invaded in 2, bile duct in 1, lymph node metastasis in 2, cirrhosis in 1, and peritoneal effusion in 1. Preoperative diagnosis was correct in only 2 cases and the other 5 cases were misdiagnosed by CT. ConclusionsThe cHCC-CC possesses some characteristic appearances on CT. Analyzing the characteristics carefully combining with symptom and cytological examination of hydrothorax can reduce the incidence of misdiagnosis.