Cytomorphological Features as a Subtyping Tool of Non-Small-Cell Lung Cancer in Brushing Bronchoscopic Samples.

Background and Objective: Nowadays, the separation of adenocarcinomas (ADCs) and squamous cell carcinomas (SCCs) is crucial given that there are new specific targeted therapies. So, the aim of this study was to examine the differences in cytomorphological features between ADC and SCC in bronchoscopic brush samples. Material and Methods: The retrospective study was conducted over a 3-year period at Western Balkan University Hospital. All brushing samples were analysed. According to the histopathological report, patients were classified into ADC and SCC groups. The cytomorphological features analysed in 95 samples were presence of necrosis, cell distribution, nuclear atypia, size of nuclei, and visibility of nucleoli. Statistical analysis was performed in JASP, and Results: The necrotic background was more frequent in SCC samples. Small clusters sized ≤200 µm were found in 17.95% of samples from the SCC group and 53.57% in the ADC group. Large clusters sized >400 µm were found in 43.59% in the SCC group, while in the ADC group, it was found in 5.36%. There were no differences in nuclear atypia between groups. Nuclei that were >5x lymphocyte size were found more often in samples from ADC than in the SCC group (37.50 vs 10.25%). In 89.75% of samples from the SCC group, nuclei were ≤5x lymphocyte sizes, while in the ADC group, the percentage was 63.5%. Nucleoli were more often visible in samples from the ADC group compared to the SCC group (92.86% vs 64.10%, Conclusions: Small clusters, large nuclei, and visible nucleoli were more frequent in the ADC group (