Objective:This study aimed to analyze clinicopathological and prognostic features of four rare pathological subtypes of primary liver malignancies to make better understanding of their clinical features.Methods:The clinicopathological data of 114 patients who were diagnosed with histologically proven four subtypes:clear cell carcinoma (CCC),giant cell carcinoma (GCC),sarcomatoid carcinoma (SC),and combined hepatocellular-cholangiocarcinoma (CHC) between October 1998 and August 2015 were reviewed.Their survival data were compared with those of 908 patients with histologically proven common hepatocellular carcinoma (HCC) (early-and advanced-stagr HCC) during the same period.Results:The outcome of the CCC group was better than that of the other three subgroups,and was similar to that of the early-stage HCC group.Also,the smallest tumor size and the highest incidence of pseudocapsule formation were observed in the CCC group.The SC group had the worst outcome among these four subgroups;the prognosis was much poorer than that of any other subgroups,even poorer than that of the advanced-stage common HCC group.No statistical difference was observed between the GCC,CHC and advanced-stage HCC groups on survival analysis.The incidences of tumor vascular emboli,TNM staging and non-radical resection were three risk factors of the prognosis.Conclusions:CCC is a low-degree malignancy and relatively favorably prognostic subtype of HCC.However,GCC,SC,and CHC are three rare high-degree malignancy subtypes of HCC with poor prognosis.