NCIt definition : A subtype of hepatoblastoma characterized by the presence of an epithelial component
and absence of mesenchymal elements. It includes hepatoblastoma with pure fetal epithelial
differentiation, hepatoblastoma with combined fetal and embryonal epithelial differentiation,
macrotrabecular hepatoblastoma, and small cell undifferentiated hepatoblastoma (small
cell undifferentiated hepatoblastoma with loss of INI1 nuclear staining should be
classified as rhabdoid tumor).;