Use of Immunohistochemical Markers in Differentiation of Hepatocellular Carcinoma from Intrahepatic Cholangiocarcinoma and Metastatic Adenocarcinomatous Deposits in the Liver from Colon: A Cross-sectional Study.

Introduction: Hepatocellular Carcinoma (HCC) is a major worldwide health problem due to its high incidence and mortality rates. The liver often becomes a site for metastasis from various primary locations, benefiting from its abundant blood supply. Distinguishing liver metastatic tumours from HCC can pose a diagnostic challenge, significantly impacting prognosis and treatment decisions. Aim: To differentiate between HCC, Intrahepatic Cholangiocarcinoma (ICC), and metastatic colonic adenocarcinoma in the liver using Hep par-1, Cytokeratin (CK) 7, CK19, and CK20 as immunohistochemical markers. The manual Tissue Microarray (TMA) technique was employed for present study. Materials and Methods: The present cross-sectional study was conducted in Department of Pathology at Government Stanley Medical College, Chennai, Tamil Nadu, India, spanning a three-year duration from July 2012 to June 2015. A total of 60 cases diagnosed histologically with HCC, ICC, and metastatic colonic adenocarcinoma in the liver were included. The manual TMA technique was used to create recipient blocks, and immunohistochemistry was performed to assess the expression of Hep par-1, CK7, CK19 and CK20. The sensitivity, specificity, Positive Predictive Value (PPV), and Negative Predictive Values (NPV) of these markers in HCC, ICC, and metastatic colonic adenocarcinoma in the liver were analysed and tabulated using statistical software Statistical Package for Social Sciences (SPSS) version 16.0. Results: The study included a total of 60 cases, with 40 (66.7%) males and 20 (33.3%) females, ranging in age from 27 to 73 years with a mean age of 51.3 years. Among the cases, there were 30 (50%) cases of HCC, 14 (23%) cases of ICC, and 16 (27%) cases of metastatic colonic adenocarcinoma in the liver. The sensitivity, specificity, and PPV of Hep par-1 in distinguishing HCC from ICC and metastatic deposits were 80%, 100%, and 100%, respectively. The NPV of Hep par-1 in distinguishing HCC from ICC and metastatic deposits was 70% and 72%, respectively. The sensitivity, specificity, PPV, and NPV of CK7 in distinguishing ICC from HCC were 3.3%, 50%, 6.3%, and 34.1%, respectively. The sensitivity, specificity, PPV, and NPV of CK19 in distinguishing HCC from ICC and metastatic deposits were 0%, 50%, 0%, and 33.3%. The sensitivity, specificity, PPV, and NPV of CK20 in distinguishing HCC from ICC and metastatic deposits were 0%, 53.3%, 0%, and 34.8%, respectively. Conclusion: In conclusion, it was found that a panel of markers including Hep par-1, CK7, CK19 and CK20 can differentiate between HCC, ICC, and metastatic colonic adenocarcinoma in the liver. This differentiation is crucial for determining the appropriate treatment for patients by understanding the exact behaviour of the tumour. [ABSTRACT FROM AUTHOR]