DNA contents in Wilms' tumors. A cytofluorometric study.

Cytofluorometric measurement of nuclear DNA was performed on individual tumor cells isolated from paraffin sections of Wilms' tumors. The DNA distribution of one untreated primary tumor showed the first major peak near the diploid range and the second peak in the tetraploid range. There were many cells having amounts of DNA interspersed between the diploid and tetraploid range. Polyploid cells were not observed. Most of the Wilms' tumor cells had a higher diploid DNA value than the small lymphocytes of the control cells. The primary tumor and its metastases showed similar DNA distribution patterns. After treatment, the distribution pattern showed a reduction in number of cells between the diploid and tetraploid range and in the tetraploid range, with the greater number of cells being found in the diploid range. Though the phases of the cell cycle are not always clearly detectable by cytofluorometry, the cells of the untreated Wilms' tumor were distributed into the phases of the cell cycle as follows: 65.9% in G0 and G1 phases; 31.2% in S-phase; and 2.9% in G2 and M phases.