Abstract
Hepatoblastoma (HB) and hepatocarcinoma (HC) comprise 2/3 of primary hepatic tumors of infants and children. As many as 1/3 of patients whose HB have been completely excised do not survive. In Children's Cancer Group Studies 60% of patients whose HB or HC (regardless of histology) were completely excised and treated with chemotherapy were disease free at 24 months; there was no significant difference in median survival between HB and HC; the fibrolamellar variant of HC was more readily resectalbe than typical HC but its unique histology did not signal a better outcome; mitotic activity in HB was associated with a poor prognosis; tumor necrosis and vascular invasion did not influence prognosis; pure fetal hisotlogy in completely resected HB was associated with improved outcome when compared with all other completely resected HB histologic subtypes; a "favorable" effect of pure fetal histology was not apparent for tumors which could not be completely resected; the absence of mitotic activity and the presence of differentiated elements such as osteoid or chondroid matrix and squamous epithelium was associated with improved survival in unresectalbe HB. DNA content of some HB correlates with prognosis. 50% of anaplastic or embryonal histology HB that exhibit DNA aneuploidy, also demonstrate vasuclar invasion and poor outcome. Chemother-apy aids surgical management of HB and HC rendering 59% of 34 unresectable tumors amen-able to later removal. In such cases, HB had a superior prognosis to HC. Tumors made resectable by chemotherapy may exhibit extensive necrosis. Treated HB speclmens undergo "changes" in histol-ogy and may revert solely to differentiated mesen-chymal elements. This chemotherapy effect may be important to the success of liver transplantation for unresectabel HB since vascular invasion has been associated with unfavorable results. Trisomy 20, trisomy 2q, double minute chromosomes, and translocation of 22q to 10q have been demonstrated in HB. Children of families with familial adenomatous polyposis are at increased (800 fold) risk for developing HB; their HB may be pathogenetically and clinically unique. Malignant rhabdoid tumor of the liver is a clinicopathologic entity characterized by presentation in early life, spread at time of diagnosis, a rapidly fatal course and male predominance. At least case appears to have responded to 11 month's chemotherapy so that the necrotic hepatic tumor could be removed and pulmonary metastases were no longer visible in imaging studies.
