Can Mitotic Figures in Hyperchromatic Crowded Groups be Cytodiagnostic Criteria for High-Grade Squamous Intra-epithelial Lesions?

Aims: The present study aimed to investigate whether the presence of mitoses in hyperchromatic crowded groups (HCGs) in cervical cytological specimens can serve as cytological criteria for high-grade squamous intra-epithelial lesions (HSILs). Methods and Material: Various parameters were examined, including the frequency of mitotic figures per high power field (HPF) in Pap, hematoxylin eosin (HE) samples, and PHH3 immunocytochemical (ICC) and immunohistochemical (IHC) analyses. Results: In the Pap and PHH3-ICC samples, the number of mitotic figures observed in HCGs was significantly higher in HSIL (P < 0.001) compared to other groups. Furthermore, the frequency of observing two or more mitoses was significantly higher in HSIL (Pap: P = 0.002, PHH3-ICC: P < 0.001) than in low-grade squamous intra-epithelial lesions (LSILs). Moreover, a comparison between Pap samples and PHH3-ICC showed that the frequency of two or more mitoses was significantly higher in the PHH3-ICC analysis of HSIL (P = 0.042). Regarding HE and PHH3-IHC samples, counting the number of mitoses in the lower and middle/upper layers of the squamous epithelial layer revealed that HSIL had a significantly higher value (HE: P = 0.0089, PHH3-IHC: P = 0.0002) than LSIL in the middle/upper layers. Conclusions: Hence, the presence of two or more mitotic figures in HCGs per HPF in cervical cytology indicates a suspicion of HSIL. The detection of mitoses in PHH3-ICC samples is more sensitive and easier to observe than in Pap samples, making it a valuable mitotic marker.