Primary malignant hepatic tumours in childhood.

Twenty-four cases of hepatoblastoma, 14 cases of hepatocellular carcinoma and three cases of malignant mesenchymoma out of a total of 54 primary liver tumours were studied by light microscopy and immunohistochemistry. A remarkable finding in one case of hepatoblastoma and one case of hepatocellular carcinoma was a sarcoid-like reaction in the tumour tissue. Three cases of hepatoblastoma presented a macrotrabecular pattern. Among hepatocellular carcinomas, three cases corresponded to the fibrolamellar variant. By immunohistochemistry, the proportion of cases with positive staining for alpha 1-fetoprotein was higher in hepatoblastoma than in hepatocellular carcinoma. HBs-antigen could be demonstrated in non-neoplastic liver cells in two cases of hepatocellular carcinoma, but not in the tumour cells. No strong correlation between histological pattern and prognosis could be established in hepatoblastoma. However, there was a tendency to more aggressive biological behavior in cases with pronounced mitotic activity. The number of mitoses in hepatoblastoma varied widely. As in previous studies, patients with the fibrolamellar variant of hepatocellular carcinoma fared better than those with the classical type of this tumour. Prognosis in malignant mesenchymoma was not as poor as suggested from previous studies.