Flow cytometric DNA-analysis of cells obtained with fine needle aspiration biopsy of the breast.

In 221 consecutive, unselected palpable breast lesions, evaluated by aspiration biopsy, flow cytometric DNA analysis was performed on cell material remaining in needle and syringe after smears had been prepared. DNA histograms were obtained in 186 cases, whereas in 44 samples the cell number was too low for detailed estimation of cell kinetics. Aneuploidy was observed in 71 of 90 samples where cancer cells were detected by cytology, in four of 20 samples where breast cancer could only be suspected and in 12 of those 76 where no cancer cells occurred in cytologic specimens. The average S-phase and S+G2M values were higher in aneuploid than in diploid cell samples. In the group of 40 cases (34 breast cancers, 6 benign lesions) comparative analysis of DNA histograms obtained on aspirates and tissue fragments revealed a concordance in 88.9%. Modified radical mastectomy was performed in 41 breast cancers and in 33 cases ductal infiltrating carcinomas were recognized by histology and scored according to Bloom-Richardson score. Cell features assessed by cytology in these cases did not correlate with histology. In most cases, however, nuclear polymorphism and numerous naked nuclei were present in cytologic specimens. These alterations, characterized as score 3, reflect values of DNA-index in compartment of 1.4-1.8.