Liquid-Based Cytology in Fine-Needle Aspirates of the Thyroid and Breast

Liquid-based cytology (LBC) is becoming more widely used in analyzing the fine-needle aspirates (FNAs) from various organs, including the thyroid and breast. Compared to the conventional smear, LBC can achieve more consistent cellularity and evenly distributed mono-layered cell preparations and it can diminish the obscuring background, thus lower the rate of 'unsatisfactory' specimens. The cytomorphological details are better preserved with LBC, and it also provides the opportunity to perform ancillary tests such as immunocytochemical or molecular studies. It requires less time and manpower for screening, too. Yet there are drawbacks for the liquid-based technique. The cell clusters tend to be more fragmented and they often lose their typical structural characteristics that may have helped in making a diagnosis. Some useful background material such as colloid and mucin is diminished. However, LBC still retains many of the cytological features of a conventional smear and possesses unique characteristics as well. Here, some of the typical cytological findings of the liquid-based technique for FNA of the thyroid and breast are reviewed. Experience, and awareness of the cylomorphological characteristics of liquid-based technique in non-gynecological aspirates is crucial for correct interpretation.