Hanaa Atwa - Pathology Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
Hanan Mohammed - Pathology Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
Ihab Matar - Surgical Oncology Department, Al -Ahrar Zagazig Teaching Hospital, Zagazig, Egypt
Heba Taha - Medical Oncology Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
Salem Mohamed - Internal Medicine Department, Gastroenterology and Hepatology Unit, Faculty of Medicine, Zagazig University, Zagazig, Egypt

Background: Hepatocellular carcinoma (HCC) is the most common primary liver cancer. Pathologic differentiation between HCC from metastatic carcinoma and cholangiocarcinoma has critical therapeutic implications. However, it is occasionally challenging and sometimes requires immunohistochemical panels. Recently, Arginase- ۱, MOC-۳۱, and CDX۲ have been introduced for the differentiation of these tumors. This study was conducted to determine the value of expression of Arginase-۱, MOC- ۳۱, and CDX۲ in differentiating primary carcinoma of the liver from cholangiocarcinoma and metastatic adenocarcinoma to the liver. Methods: ۵۰ cases of HCC, ۲۰ cases of metastatic colonic carcinoma to the liver, and ۱۰ cases of cholangiocarcinoma were evaluated for immunohistochemical expression of Arginase-۱, MOC-۳۱, and CDX۲. Results: Arginase-۱ was positive in ۴۵ (۹۰%) of HCC cases and negative in metastatic carcinoma and cholangiocarcinoma cases. MOC-۳۱ was positive in ۱۹ (۹۵%) of metastatic colonic adenocarcinoma cases and ۱۰ (۱۰۰%) of cholangiocarcinoma cases, while it was negative in HCC cases. CDX۲ was positive in ۱۸ (۹۰%) of metastatic carcinoma cases while it was negative in cholangiocarcinoma cases. The sensitivity of Arginase-۱ for HCC, MOC-۳۱ for MC, and CDX۲ for metastatic colonic carcinoma in the studied groups was ۹۵%, ۱۰۰%, and ۹۸%, respectively, whereas its specificity was ۱۰۰%, ۹۶.۷%, and ۶۰%, respectively. The difference of Arginase-۱, MOC- ۳۱, and CDX۲ expressions in HCC, cholangiocarcinoma, and metastatic colonic adenocarcinoma were statistically significant (P<۰.۰۰۱). Conclusion: Our study revealed that Arginase-۱, MOC-۳۱, and CDX۲ expression are suitable IHC markers in the differential diagnosis of HCC, cholangiocarcinoma, and metastatic colonic adenocarcinoma.

Arginase-۱, MOC۳۱, CDX۲, Hepatocellular carcinoma (HCC), Cholangiocarcinoma (CC), Metastatic colonic carcinoma