OBJECTIVETo investigate the clinicopathological features and prognostic factors of primary clear cell carcinoma of the liver (PCCCL).

METHODSThe clinical data of 41 PCCCL patients who underwent hepatic resection for PCCCL from October 1998 to June 2012 in our department were retrospectively analyzed. There were 31 male and 10 female patients. The median age was 56 years (range, 25 to 80 years), and the diagnosis was confirmed by postoperative pathological examination. The data of 106 well or moderately differentiated non-clear cell hepatocellular carcinoma (HCC) patients and 86 poorly differentiated non-clear cell HCC patients who underwent hepatic resection in the same period in our hospital in the same period were compared. The χ(2) test or Fischer's exact test, as appropriate, was used to compare group frequencies. Survival analysis was estimated by Kaplan-Meier method. Cox proportional hazards model was used in multivariate analysis.

RESULTSThe proportion of fibrous capsule formation in the PCCCL tumors (46%, 19/41) was significantly higher than that of the other two groups (P < 0.05), whereas the PCCCL group had a lower rate of intravascular tumor embolus (2/41) and vascular invasion (1/41) (P < 0.05). The median survival time of PCCCL group was 65 months, the 1-, 3-, 5-year survival rates for PCCCL patients were 90.2%, 67.4% and 42.0%, significantly better than that of poor differentiated NCCHCC group's (82.9%, 33.3%, 7.2%, P < 0.01). However, there were no statistic significant differences between PCCCL group and well or moderately differentiated NCCHCC group (84.7%, 55.7%, 34.4%, P > 0.05). Tumor capsule formation was an independent favorable prognostic factor. In contrast, preoperative serum α-fetoprotein (AFP) level and hepatitis B virus infection were independent unfavorable prognostic factors for PCCCL.

CONCLUSIONSPCCCL is a rare, low degree malignant pathological subtype of HCC. Surgical resection may achieve favorable prognosis and even long-term survival.