Discriminating hepatocellular carcinoma from metastatic carcinoma on fine‐needle aspiration biopsy of the liver: The utility of immunocytochemical panel

Abstract

The cytomorphologic features of hepatocellular carcinoma (HCC) in fine-needle aspiration (FNA) biopsy are well described. However, correctly diagnosing HCC on cytologic features alone and differentiating it from metastatic adenocarcinoma (MAC) remains a challenge. Studies have recommended the use of various immunocytochemical (ICC) stains to aid in the diagnosis and distinction of these tumors with variable success rates. In this study, we evaluated a panel of seven ICC stains, HepPar1, glypican-3, polyclonal and monoclonal carcinoembryonic antigen (pCEA, mCEA), MOC-31, CK7, and CK20, in 42 FNA cases of HCC and 48 FNA cases of MAC. The aim was to identify the most sensitive and specific markers and the best panel for accurate diagnosis. Overall, 38 of 42 HCC and 44/48 MAC tumors were correctly identified by a panel of four markers, CK7, MOC-31, HepPar1, and glypica-3, with accuracy rate of 90.5 and 91.7%, respectively. In the HCC group, glypican-3 was most sensitive and detected in 34/42 (81%), whereas HepPar1 and pCEA were less sensitive and detected in 30/42 (71.4%) and 21/42 (50%), respectively. In the MAC group, MOC-31 was most sensitive and detected in 38/48 (79.2%), followed by CK7 in 20/48 (41.7%). Stepwise logistic regression analysis showed that a panel of glypican-3, HepPar1, MOC-31, and CK7 is most helpful in diagnosing and accurately differentiating HCC from MAC on FNA biopsies of the liver. We conclude that a panel of HepPar1, glypican-3, MOC-31, and CK7 accurately and statistically significantly differentiates these two malignancies (P < 0.05).