Evaluation of Specimen Adequacy and Uniformity of Cellular Distribution in OralCytology: A Comparative Study of Conventional and Liquid-Based Cytology

The incidence and mortality rates of oral and pharyngeal cancer in Japan continue to increase. This study aimed to evaluate and compare specimen adequacy between conventional and liquid-based cytology（LBC）in oral exfoliative cytology through quantitative image analysis. Specimens were self-collected by 71 university dental students using conventional and LBC methods. The specimens were stained using the Papanicolaou method and analyzed using ImageJ software to quantify parameters such as cell smear area, uniformity of cellular distribution, and cluster formation. LBC demonstrated significantly higher median values for cell smear area, green cell area, and uniformity in cellular distribution compared to conventional cytology（p＜ 0.001）. The conventional cytology, although effective, showed greater variability in non-uniformity of cellular distribution and lower overall cell counts. Additionally, LBC specimens presented fewer but smaller cell clusters, indicating superior uniformity, likely due to the enhanced preparation process inherent to LBC. These findings suggest that LBC provides more consistent specimen adequacy and uniformity of cellular distribution, which is essential for accurate cytological assessment. By offering objective metrics to compare cytology methods, this study supports the adoption of LBC in oral cancer screening, particularly in cases where scalpel biopsy is declined. The differences in specimen quality and uniformity between the two methods highlight the utility of LBC as a viable improvement over conventional cytology, aligning with the need for reliable and accessible oral cytology techniques.