Histopathology and prognosis in childhood hepatoblastoma and hepatocarcinoma.

To determine the relationship between outcome and histologic type, the authors examined data from 168 cases of hepatoblastoma (HB) and 28 cases of hepatocarcinoma (HC) accrued from children over a 14-year period. After adjustment for stage of disease, there was no significant difference in median survival between HB and HC. Mitotic activity was associated with poor prognosis. Necrosis or vascular invasion did not influence prognosis. In 55 cases of completely resected HB, pure fetal histologic type (PFH) was associated with improved survival when compared with all other histologic patterns of HB (92% versus 57% 24 months' survival; P = 0.02). A prognostic effect of PFH was not demonstrable in incompletely resected HB, but the absence of mitoses and the presence of differentiated mesenchymal elements improved survival. The fibrolamellar pattern of HC demonstrated survival similar to that of the typical pattern of HC. The authors conclude that features consistent with differentiation in HB convey improved prognosis for survival. These observations may be important in designing future therapy for children with hepatic tumors.