Document Type : Original Article
Authors
1
Dental Research Center, Research Institute for Dental Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
2
Dept. of Oral and Maxillofacial Pathology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
3
Dept. of Pathology, Cancer institute, Imam Khomeini Hospital Complex (IKHC), School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
4
School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
10.30476/dentjods.2026.111171.3013
Abstract
Background: Cytokeratin 17 (CK17) is a cytoskeletal protein that is absent in stratified epithelia but can be induced in activated keratinocytes. The precise mechanisms of CK17 in premalignant and malignant progression remain unclear. In addition, accurate histopathological differentiation between oral lichen planus (OLP) and epithelial dysplasia remains a diagnostic challenge.
Purpose: The present study was designed to evaluate CK17 expression using immunohistochemical analysis across seven diagnostic groups, including normal oral epithelium, OLP, low-grade dysplasia, high-grade dysplasia, conventional squamous cell carcinoma (SCC), papillary SCC, and verrucous carcinoma, to determine whether CK17 could serve as an adjunctive biomarker for assessing epithelial dysplasia in OLP.
Materials and Method: In this retrospective cross-sectional study, 69 formalin-fixed para-ffin- embedded tissue samples were assessed. Some blocks contained more than one histopathologically distinct area, resulting in 88 evaluable tissue sections for immunohistochemical analysis. Immunohistochemical staining was performed using a monoclonal anti-CK17 antibody. CK17-positive epithelial cells were counted in at least three randomly selected fields at 200× magnification. Cases with <5% reactive cells were considered negative, wh-ereas those with >5% reactivity were classified as positive. Among positive cases, sections showing >60% positive cells were defined as strong expression, and those with <60% as weak expression. Statistical analyses were conducted using the independent-samples Kruskal-Wallis test and the Bonferroni correction to address multiple testing in SPSS version 28.
Results: Strong CK17 expression (>60% positive cells) was observed in 67 of 88 evaluated samples (76.1% of the total cohort). A statistically significant difference in CK17 expression scores was observed among diagnostic groups (Kruskal–Wallis H(6)=80.87, p Value<0.001). However, pairwise comparisons with Bonferroni adjustment showed no significant difference between OLP and SCC (Adj. p=1.000) and between OLP and high-grade dysplasia (Adj. p=1.000).
Conclusion: CK17 expression was strongly positive in high-grade dysplasia and in all examined malignant lesions, including SCC, papillary SCC, and verrucous carcinoma, supporting its role as a marker of advanced epithelial alteration. However, its similarly high expression in OLP indicates that CK17 lacks sufficient specificity to reliably distinguish immune-mediated epithelial changes from dysplastic transformation.
Keywords
