Diagnostic accuracy of clathrin heavy chain staining in a marker panel for the diagnosis of small hepatocellular carcinoma

The American Association for the Study of Liver Diseases guidelines recommend the use of all available markers for improving the accuracy of the diagnosis of small hepatocellular carcinoma (HCC). To determine whether clathrin heavy chain (CHC), a novel HCC marker, is effective in combination with glypican 3 (GPC3), heat shock protein 70, and glutamine synthetase, we compared the performances of a three-marker panel (without CHC) and a four-marker panel (with CHC) in a series of small HCCs (≤2 cm) and nonsmall HCCs by core biopsy with a 20- to 21-gauge needle. The series included 39 nonsmall HCCs and 47 small HCCs (86 in all); the latter showed a well-differentiated histology [small grade 1 (G1)] in 30 cases (63.8%). The panel specificity was analyzed with the adjacent/extranodular cirrhotic liver (n = 30) and low-grade (n = 15) and high-grade dysplastic nodules (n = 16) as a control group. Absolute specificity (100%) for HCC was obtained only when at least two of the markers were positive (which two markers were positive did not matter). The addition of CHC to the panel increased the diagnostic accuracy for small HCCs (from 76.9% to 84.3%), and there was an important gain in sensitivity (from 46.8% to 63.8%). The four-marker panel had lower rates of accuracy (67.4%) and sensitivity (50%) for small G1 HCCs versus nonsmall G1 HCCs (93.9% and 88.2%, respectively). In seven cases (including six small G1 HCCs), there was no staining with any of the markers. Cirrhotic control livers were stained for CHC in four cases (13.3%) and for GPC3 in one case (3.3%). Conclusion: The addition of CHC to the panel supports the diagnosis of small HCCs in challenging nodules on thin core biopsy samples. Small G1 HCCs include a group of earlier tumors characterized by a more silent phenotype and the progressive acquisition of the markers under study. The search for additional markers for early HCC diagnosis is warranted.