Hormone receptors in hepatoblastoma: a demonstration of both estrogen and progesterone receptors.

A case of mixed hepatoblastoma occurring in a four-year-old girl is described. Light and electron micrographs illustrate a predominant mesenchymal component and a less conspicuous epithelial element. The tumor contained specific cytosolic protein receptors for estrogen and progesterone. The estrogen receptor titer was 10.5 fmol/mg cytosol protein and the progesterone receptor titer was 62.2 fmol/mg cytosol protein.