Clinicopathological features and differential diagnosis of hepatocellular carcinoma in extrahepatic metastases.

Extrahepatic metastasis of hepatocellular carcinoma (HCC) may cause a diagnostic problem. All 195 cases of histologic and immunostained sections were reviewed retrospectively in one center. The expression of arginase-1 (Arg-1), hepatocyte paraffin-1 (HepPar-1), glypican-3 (GPC-3), and α-Fetoprotein (AFP) was evaluated. Eighty cases of metastatic tumors of the liver were also collected to verify their effectiveness. Totally 151 cases had previous history of HCC, in whom 49 had history of liver transplantation. Forty-four cases were diagnosed as metastatic HCC at initial presentation. The most common extrahepatic metastatic sites were bone (57%), followed by lung, lymph node, etc. Around 19 cases were positive for 1 marker, 22 were positive for 2 markers, 95 were positive for 3 markers, and 59 were positive for 4 markers. With the number of antibody increased in the panel, the negative cases decreased. The sensitivity of ARG, GPC-3, HepPar-1, and AFP was 82.6%, 89.2%, 83.6% and 53.8%, and the specificity was 98.3%, 94.8%, 96.2% and 100%, respectively. These data suggest that the panel of ARG-1, GPC-3, HepPar-1 and AFP has a high sensitivity and specificity to differentiate HCC from non-HCC. This study indicated that HCC should be considered when diagnosing metastasis of unclear origin. It is recommended to use the panel of ARG-1, GPC-3, HepPar-1 and AFP to differentiate HCC from non-HCC in extrahepatic metastasis, because of their sensitivity and specificity, especially in poorly differentiated lesions.