FLOW CYTOMETRIC EVALUATION OF NUCLEAR-DNA CONTENT IN HEPATOBLASTOMA -FURTHER EVIDENCE FOR THE INHOMOGENEITY OF THE DIFFERENT SUBTYPES

The DNA ploidy pattern of nine hepatoblastomas and three normal liver specimens was investigated by flow cytometry. Areas of unlike differen tiation in the same tumor were investigated separately, Normal liver t issue and the fetal subtype were always diploid, Aneuploidy was found in the embryonal subtype. The one case of small cell tumor was also di ploid. When the fetal and embryonal areas of the same tumor were analy zed together, there was always an aneuploid peak in the histogram, The re are obvious differences in DNA ploidy among the various hepatoblast oma subtypes, Differences in methods used, including the failure in so me studies to evaluate areas of unlike differentiation in the same tum or separately, probably account to some extent for the conflicting res ults of previously reported studies, When flow cytometric analysis of the DNA content of a hepatoblastoma is performed, it is important to e nsure that the various types of differentiation in the tumor are repre sented adequately in the material investigated, especially when conclu sions about the prognosis are to be based on these findings.