Liquid-based cytology in breast fine needle aspiration. Comparison with the conventional smear.

OBJECTIVE To compare the various cytologic features on AutoCyte Prep (ACP) (AutoCyte, Inc., Burlington, North Carolina, U.S.A.) and conventional preparation (CP) specimens from breast fine needle aspiration cytology material with a semi-quantitative scoring system. STUDY DESIGN A total of 100 randomized cases were studied. In each case, 2 passes were performed. One pass was used for CPs (Giemsa and Papanicolaou stain). The other pass produced material for the ACP technique and Papanicolaou stain. Both the conventional and liquid-based preparations were studied independently by two observers and compared for cellularity, obscuring and/or informing background, representative diagnostic material, preservation of cytomorphologic features, presence of monolayer cells and architectural arrangement. RESULTS Comparing the two preparations, the results were as follows: (1) ACP was superior to CP in 2 features, lack of obscuring background and presence of monolayer arrangement with preservation of cell architecture; (2) ACP was inferior to CP in 1 feature, lack of informing background; and (3) ACP was equal, with small deviations, to CP in the rest of the features evaluated: cellularity, representative diagnostic material, preservation of cell morphology and architectural arrangement. CONCLUSION The new technology of liquid-based cytology in breast FNA showed a good correlation with CP plus the advantages of: (1) easier and less time consuming evaluation of cell morphology (clear background, no overlapping, smaller area to screen); (2) reproducibility, a factor of great importance to quality control; and (3) possibility of adjunctive investigations (immunocytology, flow cytometry) on the same material.