Diagnostic Value of Arginase1 and Glypican3 in Differential Diagnosis of Hepatocellular Carcinoma, Cholangiocarcinoma and Metastatic Carcinoma of Liver

Hepatocellular carcinoma is the most common primary liver cancer. Pathologic distinction between Hepatocellular Carcinoma (HCC) and adenocarcinoma (Cholangiocarcinoma (CC) and Metastatic Adenocarcinoma (MA)) can be challenging and sometimes requires immunohistochemical panels. Recently, Arginase1 (ARG1) and Glypican3 (GPC3) have been introduced for differentiation of these tumors. The aim of this study was to determine the diagnostic accuracy of ARG1 and GLP3 in differential diagnosis of liver tumors. Eightynine formalinfixed paraffinembedded tissue blocks including 43 cases of documented HCCs, 19 cases of documented CC, and 27 cases of MA involving the liver (15 colon, 5 stomach, 3 pancreas, 2 gallbladder, 1 duodenum and 1 ampulla of vater) were evaluated for immunohistochemical expression of ARG1 and GPC3. Arginase1 and GPC3 demonstrated diffuse staining, as reactivity in amp;gt; 97% of HCCs, whereas only one (5.3%) and 2 (10.5%) of 19 CC cases show positive staining for GPC3 and ARG1, respectively. The expression of both markers in MA showed 6 (22.2%) for ARG1 and 3 (11.1%) for GPC3, especially with colorectal origin. Our findings showed a statistically significant difference between ARG1 and GPC3 expression in HCC, CC and MA. The findings of this study reveal that both ARG1 and GPC3 are helpful IHC markers to separate HCC from CC and MA. Furthermore, ARG1 shows 100% sensitivity and 82.6% specificity for the diagnosis of HCC whereas GPC3 demonstrated 97.7% sensitivity and 91.3% specificity for the diagnosis of this tumor.