OBJECTIVETo explore the expression and diagnostic significance of glypican-3 (GPC3) in hepatoblastoma.

METHODSFive tissue microarray paraffin blocks were constructed to include 54 cases of hepatoblastoma. The tumor tissue samples were obtained from 3 surgical biopsies, 33 needle biopsies, 5 stage I resection tumors, and 13 stage II resection tumors after transcatheter arterial chemoembolization. Ten samples of non-neoplastic hepatic tissue adjacent to tumor were used as control. Immunohistochemical staining of GPC3 (clone 1G12) was performed. Among the 54 cases of hepatoblastoma, 22 cases were fetal subtype, 24 cases were mixed fetal and embryonal subtype and 8 cases were mixed epithelial and mesenchymal type.

RESULTSGPC3 was positive in fetal epithelial cells (54/54, 100%), but negative or weakly positive in embryonic epithelial cells in all cases of hepatoblastoma. Undifferentiated small cells and all mesenchymal components were negative for the expression. Non-neoplastic hepatocytes adjacent to tumor were negative for GPC3 expression (0/10) .

CONCLUSIONSFetal epithelial components of hepatoblastoma express GPC3 protein detectable by immunohistochemistry. Normal hepatocytes after birth, small cell undifferentiated and embryonic epithelial components of hepatoblastoma do not or weakly express GPC3 protein. Therefore, GPC3 immunohistochemistry offers a valuable aid to the diagnosis of hepatoblastoma in infants and children.