The Diagnostic Significance of Cytokeratin 13 & 17 Expression in Oral Mucosal Biopsies by Immunohistochemical Technique

Abstract

Objective: To find out immunohistochemical (IHC) profile of cytokeratin 13 and 17 expression in oral premalignant and malignant epithelial lesions.

Methodology: This descriptive cross-sectional study was conducted at, pathology department of Liaquat University of medical and health science Jamshoro from January 2017 to June 2019. Excisional biopsy samples of patients of all age groups, both gender with complain of oral mucosal epithelial lesions were enrolled. Oral mucosal biopsies were fixed in 10% formalin, routinely processed, and stained with H&E for histopathological diagnosis. Immunohistochemistry for Cytokeratin 13 and 17 was performed on paraffin sections after deparaffinization and blocking of endogenous peroxidase activity. Tissue sections were kept moist throughout the procedure and mounted on FLEX IHC slides. All the relevant pathological and clinical data were recorded using study proforma and analyzed by SPSS version 20.

Results: Patient’s mean age was 40.45+11.94 years and males were in majority 63.4%. Buccal mucosa, cheek and tongue were most common sites of biopsy, 32.8%, 21.6% and 31.3% respectively. CK13 was positive among 73 cases. CK17 was positive among 96 cases. Leukoplakia, sub mucous fibrosis, ulcers were significantly associated with CK13 p=0.003, while leukoplakia and squamous cell carcinoma were significantly associated with CK 17 p=0.001.

Results: A total of 139 cases were included. The mean age of patients was 40.45 ± 11.94 years. Males constituted the majority (63.4%). The most common biopsy sites were buccal mucosa (32.8%), cheek (21.6%), and tongue (31.3%). Most patients (78.4%) reported symptoms for 1 to 3 months. Leukoplakia was the most frequent oral lesion, observed in 22.3% of cases.

CK13 positivity was observed in 73 cases, while CK17 was positive in 96 cases. CK13 expression was significantly associated with leukoplakia, submucous fibrosis, and ulcers (p = 0.003). CK17 expression showed significant association with leukoplakia and squamous cell carcinoma (SCC) (p = 0.001). Histologically, dysplasia was significantly associated with positive CK13 expression, whereas SCC was significantly associated with CK17 expression, both with statistically significant p-values.

Conclusion: CK13 is a useful immunohistochemical marker for epithelial dysplasia, while CK17 serves as a reliable diagnostic marker for squamous cell carcinoma. CK13 expression was significantly higher in cases of leukoplakia, submucous fibrosis, ulcers, and epithelial dysplasia. CK17 was more frequently expressed in cases of leukoplakia and SCC.