Role of glypican-3 immunocytochemistry in differentiating hepatocellular carcinoma from metastatic carcinoma of the liver utilizing fine needle aspiration cytology.

PURPOSE: Evaluation of the sensitivity and specificity of glypican3 (GPC3) in differentiating hepatocellular carcinoma (HCC) from metastatic carcinomas of the liver in cell block material.

PATIENTS AND METHODS: Sixty cell blocks were prepared from liver FNAs performed in the radiodiagnosis department, National Cancer Institute, in the period between August 2011 and May 2012. Cases diagnosed as hepatocellular carcinoma, or metastatic carcinoma were included in the study. Cell block sections were stained with anti GPC-3. Sensitivity, specificity, and positive and negative predictive values, of GPC3 were calculated. The final diagnosis was based on the triple approach of clinical data, radiological findings, as well as cytomorphologic features aided by GPC-3 results.

RESULTS: 70% of cases were diagnosed as HCC, and 30% as metastatic carcinomas. 95.2% of HCC cases expressed GPC3. Poorly differentiated cases showed the highest GPC3 sensitivity (100%), followed by moderately differentiated cases (96.5%), while well differentiated cases expressed GPC3 in 90% of cases. 83.3% of metastatic carcinomas were negative for GPC3. In this study, sensitivity of GPC-3 in HCC was 95.2%, specificity was 83.3%, positive and negative predictive values were 93% and 88.2% respectively, and total accuracy was 91.7%.

CONCLUSION: Immunocytochemical staining for GPC3 in cell block material is a highly sensitive and specific method capable of distinguishing HCC from the vast majority of metastatic carcinomas of the liver.