The Diagnostic Role of Arginase-1, MOC-31, and CDX2 in the Differentiation of Hepatocellular Carcinoma, Cholangiocarcinoma, and Metastatic Colonic Carcinoma of the Liver

Background: Hepatocellular carcinoma (HCC) is the most common primary liver cancer. Pathologic differentiation between HCC from metastatic carcinoma and cholan-giocarcinoma has critical therapeutic implications. However, it is occasionally challenging and sometimes requires immunohistochemical panels. Recently, Arginase-1, MOC-31, and CDX2 have been introduced for the differentiation of these tumors. This study was conducted to determine the value of expression of Arginase-1, MOC-31, and CDX2 in differentiating primary carcinoma of the liver from cholangiocarcinoma and metastatic adenocarcinoma to the liver. Methods: 50 cases of HCC, 20 cases of metastatic colonic carcinoma to the liver, and 10 cases of cholangiocarcinoma were evaluated for immunohistochemical expression of Arginase-1, MOC-31, and CDX2. Results: Arginase-1 was positive in 45 (90%) of HCC cases and negative in metastatic carcinoma and cholangiocarcinoma cases. MOC-31 was positive in 19 (95%) of metastatic colonic adenocarcinoma cases and 10 (100%) of cholangiocarci-noma cases, while it was negative in HCC cases. CDX2 was positive in 18 (90%) of metastatic carcinoma cases while it was negative in cholangiocarcinoma cases. The sensitivity of Arginase-1 for HCC, MOC-31 for MC, and CDX2 for metastatic colonic carcinoma in the studied groups was 95%, 100%, and 98%, respectively, whereas its specificity was 100%, 96.7%, and 60%, respectively. The difference of Arginase-1, MOC-31, and CDX2 expressions in HCC, cholangiocarcinoma, and metastatic colonic adenocarcinoma were statistically significant (P<0.001). Conclusion: Our study revealed that Arginase-1, MOC-31, and CDX2 expression are suitable IHC markers in the differential diagnosis of HCC, cholangiocarcinoma, and metastatic colonic adenocarcinoma.