COMPREHENSIVE ANALYSIS OF HISTOLOGICAL CHANGES IN THE LIP MUCOSA IN CHRONIC CHEILITIS

Abstract

Objective: To assess the relationship between epithelial and stromal changes in chronic cheilitis in order to identify prognostic criteria for malignant transformation. Methods: A retrospective analysis was performed of 46 cases of lip resections with histologically confirmed chronic cheilitis during the period from May 2022 to December 2024. Patients were divided into two groups: Group A (n=24) – without epithelial dysplasia; Group B (n=22) – with low- and highgrade epithelial dysplasia. The age and demographic characteristics of the groups did not differ significantly (p>0.05). A comprehensive morphological analysis was performed, including histology (hematoxylin and eosin staining, PAS reaction) and immunohistochemistry with CD31 antibodies to assess microvascular density (MVD) according to the Weidner method. Stromal morphometry was performed using the “Video Test-Morphology 5.2” software. Results: Dysplastic changes were identified in Group B, including disruption of keratinocyte polarity, nuclear hyperchromasia, and pathological mitoses. The karyopyknotic index was 14.6±2.1% compared with 8.2±1.4% in Group A (p<0.001). MVD was significantly higher in Group B than in Group A (26.7±4.1 vs. 18.4±3.2 vessels per field of view, ×200; p<0.001). The vascular-to-stromal ratio in Group B reached 1.38±0.12 vs. 0.92±0.09 in Group A; p<0.001. A strong positive correlation was found between the degree of dysplasia and MVD (r=0.81; p<0.01). Conclusion: Chronic cheilitis with epithelial dysplasia is characterized not only by atypia of the epithelial layer but also by remodeling of the stromal microenvironment with activation of angiogenesis. Increased MVD and the vascular-to-stromal ratio reflect the formation of a pro-oncogenic microenvironment at the precancerous stage. Quantitative assessment of MVD using CD31 demonstrates high prognostic value for determining the risk of malignant transformation. These findings support the concept of a “field of cancerization”, according to which interactions between the epithelium and stroma determine carcinogenic transformation. Incorporating morphometric parameters (MVD and the karyopyknotic index) into diagnostic algorithms may help optimize patient management by identifying a high-risk group requiring intensified surveillance or preventive treatment. The results are consistent with evidence regarding the key role of angiogenesis in the progression of precancerous conditions and support the need to introduce standardized criteria for quantitative assessment into routine histopathological practice. for more detailed stratification of oncological risk. Keywords: Vermilion border of the lips, dysplasia, microvascular density, cheilitis, CD31, angiogenesis.