Feulgen-DNA-cytophotometry on mammary tumor cells from aspiration biopsy smears.

The nuclear DNA content of cells from 20 cases of mammary aspirates was estimated by microspectrophotometry. Smears stained according to Papanicolaou were destained and Feulgen-reacted. Among the smears there were 14 with doubtless tumor cells, four with a benign cell picture, and two of a doubtful nature. The mammary lesions were in all cases verfied by histology. Measurements showed that smears of benign tumors had a diploid or diploid to tetraploid distribution of DNA. The two doubtful smears also showed the same DNA pattern, although in one case the cells were from a papillary carcinoma and in the second case from a fibroadenoma. Malignomas with a cell picture, monomorphous-atypical in Papanicolaou staining exhibited a DNA histogram with a peak in the diploid to hyperdiploid ranges. Carcinomas showing a polymorphous-atypical cell picture were characterized either by polyploid values, by a large spread, or by aneuploidy. Hence, it is impossible to safely distinguish benign cases from carcinomas by the DNA pattern, since DNA distribution is fairly identical in part of the cases in either group.