DNA in heterochromatin cytophotometric pattern recognition image analysis among cell nuclei in duct epithelium and in carcinoma of the human breast

Feulgen stained normal breast epithelium (4 cases) and breast carcinoma (8 cases) were analyzed by means of cytophotometric scanning measurements. Besides the DNA content, DNA concentration, and area of the cell nucleus, the number and absolute as well as relative amount of condensed chromatin was determined. In addition, the DNA concentration, area, and form of the condensed chromatin was evaluated. It was demonstrated that nuclear DNA is elevated (near tetraploid stemlines) in carcinoma cells, the DNA concentration is more highly variable, and that the elevated DNA amounts are largely attributable to elevated nuclear area values. The number of 'heterochromatic' particles is more variable in tumor cell nuclei than in normal cell nuclei. Significantly more chromocenters were demonstrable in only one case. The absolute DNA content in condensed chromatin of carcinoma cells is also highly variable (significantly elevated only in a single case). The most important result of the foregoing investigation seems to be that the percentage of DNA content in condensed chromatin is greatly decreased in all tumors (6%) as compared to normal cell nuclei (13%). Regarding the form of the condensed chromatin particles, the particles are more spherical in tumor cells than in normal cells. The results are discussed in relation to biochemical determinations of heterochromatin.