Significance of hepatocyte paraffin-1, cluster of differentiation 34 and cytokeratin expression in the diagnosis of alpha-fetoprotein-negative hepatocellular carcinoma

AIM: To investigate the significance of hepatocyte paraffin-1 (Hep Par-1), cluster of differentiation 34 (CD34) and cytokeratin (CK) expression in the diagnosis of alpha-fetoprotein-negative hepatocellular carcinoma (AFP(-)HCC) and in the differential diagnosis among AFP(-) HCC, intrahepatic cholangiocellular carcinoma (ICC) and metastatic adenocarcinoma (MAC).

METHODS: Paraffin-embedded surgical specimens were collected from 70 AFP(-)HCC patients, 6 ICC patients and 24 MAC patients at Nantong Tumor Hospital from 1989 to 2007. All specimens were stained immunohistochemically for Hep Par 1, CD34 and CK.

RESULTS: There were statistically significant differences in the positive expression rates of Hep Par 1 and CD34 in AFP(-)HCC, ICC and MAC (Hep Par 1: χ² = 50.7937, 9.5745 and 37.4532, respectively; CD34: χ² = 67.0330, 9.9836 and 49.3927, respectively; all P < 0.01). Significant differences were also noted in the positive expression rates of Hep Par 1, CD34, CK20 and CK19 between poorly and well differentiated AFP(-)HCC (all P < 0.01 or 0.05). The accuracy, sensitivity and specificity of combined immunohistochemical detection of Hep Par 1, CD34 and CK in the differential diagnosis among AFP(-) HCC, ICC and MAC were 90.7%, 89.8% and 93.3%, respectively.

CONCLUSION: Combined detection of Hep Par 1, CD34 and CK can improve the accuracy of diagnosis of AFP(-)HCC and of differential diagnosis among AFP(-)HCC, ICC and MAC.