Hepatocellular carcinoma: A clinicopathological and immunohistochemical study of 116 cases from a tertiary care hospital in Southern India

Abstract Background: Diagnosis of hepatocellular carcinoma (HCC) is difficult on morphology alone in poorly differentiated tumors and metastatic carcinomas. Appropriate immunohistochemical markers are required for definite diagnosis. In this article, we have analyzed the histopathological and immunohistochemical features of HCC and elucidate the best possible immunohistochemistry (IHC) marker combination by comparing the sensitivity of various markers in different grades of tumor. Methods: A total of 116 consecutive cases were analyzed retrospectively. The hematoxylin and eosin stained sections were reviewed in all the cases. IHC was done using hepatocellular specific antigen (HSA), arginase-1, glypican-3, and polyclonal carcinoembryonic antigen (pCEA). The sensitivity of various immunohistochemical markers individually as well as in combination for different tumor grades was determined. Results: Histologically, the predominant subtype comprised of classic variant (109,93.9%) followed by combined hepatocellular and cholangiocarcinoma (4,3.4%) and fibrolamellar variant (3,2.6%). Trabecular pattern was the most common histological pattern. On grading, 65,56.03% were moderately differentiated, 34,29.31% well differentiated, and17, 14.65% poorly differentiated. HSA and polyclonal-CEA showed higher sensitivity than arginase-1 and glypican-3 in well and moderately differentiated tumors. In contrast arginase-1 and glypican-3 showed better sensitivity in poorly differentiated HCC. The overall sensitivity increased to greater than 90% if HSA/polyclonal-CEA is combined with either arginase-1/glypican-3 irrespective of tumor grade. Conclusion: Majority of the tumors were classic variants and moderately differentiated. HSA along with either arginase-1 or glypican-3 is the best combination of immunomarker for identification of hepatocellular differentiation irrespective of tumor grade.