Intrahepatic cholangiocarcinoma diagnosed preoperatively as hepatocellular carcinoma

BACKGROUND: Some cases of mass-forming intrahepatic cholangiocarcinoma (ICC) are diagnosed as hepatocellular carcinoma (HCC) based on preoperative imaging and clinical findings. We investigated the backgrounds of such cases. METHODS: Sixty-seven patients with mass-forming ICC underwent surgery from 1980 to 2002. Twenty-four of these patients received a diagnosis of HCC preoperatively. We compared the group diagnosed as HCC and that diagnosed as ICC. ICC was diagnosed histopathologically in all 67 patients. RESULTS: The specific clinical findings included high rates of associated hepatitis C virus infection, high levels of serum alpha fetoprotein, lower levels of serum CA19-9, small dimension of the tumor, hypervascular staining on angiography or computed tomography, lower rates of lymph node metastasis, and high rates of HCC occurrence in the group diagnosed as HCC. None of the patients underwent extrahepatic bile duct resection and most patients did not undergo lymph node dissection in the group diagnosed as HCC. The rates of mucus secretion and the ductal expression of mucin core protein-1 (MUC1) were significantly different between the subgroups. The cumulative survival rates were significantly better in the group diagnosed as HCC than in the group diagnosed as ICC. CONCLUSION: Patients with ICC given a preoperative diagnosis of HCC had distinct clinical features and could be treated with the same operation as HCC patients.