The DNA content in the cell nuclei of trophoblastic tumors

: The DNA content in cytotrophoblast (CTB) and syncytiotrophoblast (STB) cell nuclei was assayed in tissue sections of 7 hydatidiform moles (HM) and 27 choriocarcinomas (CH). The procedure involved Feulgen's reaction and scanning cytophotometry. The analysis of summarized histograms showed the DNA distribution in CTB cell nuclei, on the one hand, and that in STB, on the other, to differ significantly in both the tumors. The HM studied cases were referred to as two subtypes on the basis of such parameters as modal class value, its ploidy and degree of nuclear poly- and heteroploidy of CTB and STB. These characteristics were used to identify three patterns of CH. A pronounced modal class (2c--4c) was typical of type 1. A wider range of modal class (2c--10c or 4c--8c) was observed in type 2. Type 3 of tumor was characterized by a pronounced polyploidy with the absence of the modal class. The analysis of individual CTB and histograms showed no significant differences between HM and CH with respect to the DNA content. An increase in the share of highly polyploid cells was associated with a shorter survival of patients.