Clinicopathological and prognostic features of primary clear cell carcinoma of the liver

AIM: Primary clear cell carcinoma of the liver (PCCCL) is a subgroup of primary hepatocellular carcinoma (HCC), pathologically characterized by diffuse clear cells of the tumor, showing a clear cytoplasm that does not stain with hematoxylin-eosin. At present, its clinicopathological and prognostic features are not fully clarified. This study aims to clarify the clinicopathological and prognostic features of PCCCL. METHODS: The clinicopathological data of 43 patients with PCCCL treated with hepatectomy in our hospital from January 1999 to December 2003 were retrospectively analyzed. RESULTS: The chi(2)-test showed a positive rate of hepatitis C virus (HCV) infection and capsule formation in the PCCCL group, which was markedly higher than in the common type HCC (CHCC) group (P = 0.000 and P = 0.005). Meanwhile, the vascular invasion rate was notably lower in the PCCCL group, but there were no significant differences between the twogroups (P = 0.129). The Kaplan-Meier method showed that the 1-, 3-, and 5-year survival rates were significantly higher in the PCCCL group than in the CHCC group (P = 0.021). The prognosis of patients in the PCCCL group was related to capsule formation, vascular invasion, liver cirrhosis, and clear cell ratio. The 1-, 3-, and 5-year survival rates were markedly higher in the group with a higher clear cell ratio than in the group with a lower clear cell ratio (P = 0.011). CONCLUSION: The notable clinicopathological features of the patients in the PCCCL group included a higher rate of HCV infection, capsule formation, and a lower rate of vascular invasion. The prognosis was better than that of the patients in the CHCC group and related to the ratio of clear cells.