Hepatoblastoma. Attempt at characterization of histologic subtypes.

This is a clinicopathologic study summarizing the experience with hepatoblastomas at Children's Memorial Hospital of Chicago between 1954 and 1981. Of 21 patients studied, 13 (61.9%) died. Three major histologic epithelial patterns were identified: fetal, embryonal, and macrotrabecular. The first two may represent different stages of cytodifferentiation of hepatoblastoma cells. The macrotrabecular type had features similar to hepatocellular carcinoma of adults, from which distinction was difficult; this type pursued an aggressive clinical course. The fetal type exhibited advanced differentiation, and two cases in this category survived after surgery only; local extrahepatic dissemination was present in other cases of the fetal type. Mixed epithelial and mesenchymal tumors constituted only 23% of this series, and none contained rhabdomyoblastic elements. Although modern chemotherapy may alter the course of this disease, the small size of this series precluded definite statements in this regard. Only patients in whom the tumor was completely excised as primary treatment became long-term survivors.