Flow cytometry in breast cancer: cell yield using two different fine needle aspiration devices

The aim of the study was to compare the quality of breast aspirates obtained by two methods of fine needle aspiration cytology (FNAC): the auto-vacuum device and the syringe pistol holder, using flow cytometry. Both techniques were used in 44 fresh surgical specimens. Subsequently, these specimens were fixed and mounted in paraffin. Both the aspirates and the de-waxed histology material were prepared for flow cytometry using a FACScan. Flow cytometry showed that the means for DNA index and S-phase fraction were similar for aspirates obtained with both techniques. Mean aneuploidy was significantly higher in the auto-vacuum device aspirates than in the surgical specimen (43.4 SD +/- 23 vs. 27.9 SD +/- 17; p = 0.04). Mean DNA index and S-phase fraction were similar in cells from aspirates and surgical specimens. It is concluded that both FNAC methods are of similar efficacy in collecting aspirates for flow cytometry.