Assessment of podoplanin lymphatic vessel density in oral epithelial dysplasia

BACKGROUND: Oral squamous cell carcinoma (OSCC) can be preceded by the appearance of lesions which have the potential to develop into cancer. Recently, it was suggested that the tumor-associated lymphatic vessels formation plays an active role in tumor progression and metastasis of several human malignancies including OSCC. There is the view that, in an individual lesion, the more severe the dysplasia, the greater the likelihood is of progression to malignancy. AIM: This study is aimed to investigate podoplanin (PDPN) immunoexpression in lymphatic vessels of oral epithelial dysplasia (OED) and to assess the lymphatic vessel density (LVD) in histologic grades of OED. MATERIALS AND METHODS: The study group comprised thirty histopathologically diagnosed cases of OED with various grades of differentiation and thirty cases of clinically normal oral mucosa. After immunohistochemical staining, cases of OED were immunohistochemically analyzed quantitatively for PDPN (D2-40) LVD. STATISTICAL ANALYSIS: The statistical analysis was done using Kruskal Wallis analysis of variance; pair-wise Tukey's post hoc test was applied to evaluate the significant differences among the mean values in different groups. Results with “P < 0.05” were considered to be statistically significant at 95% of confidence level. RESULTS: PDPN LVD scores increased with increasing grades of dysplasia. Pair-wise comparisons of the PDPN LVD scores and the histopathologic grades of OED were found to be statistically significant (P < 0.05). CONCLUSIONS: Increase in PDPN LVD in OED represents a promising tool for more wide spread studies of tumor lymphangiogenesis and its role in progression of dysplastic lesion to human cancer.