Mast cell density and angiogenesis in oral dysplastic epithelium and low- and high-grade oral squamous cell carcinoma

Objective. Oral squamous cell carcinoma (OSCC) is one of the 10 most common malignant tumors and SCC accounts for approximate to 94% of all oral malignancies. The risk of malignant transformation in dysplastic lesions is greater than that of normal oral mucosa. The definite roles of mast cells and angiogenesis in OSCC have been under debate. The aim of this study was to compare mast cell count (MCC) and microvessel density (MVD) among normal oral mucosa, oral dysplastic epithelium and low- and high- grade OSCC. Material and methods. A total of 42 specimens of OSCC (21 high- and 21 low-grade) were collected, along with six normal and 22 dysplastic oral mucosa. The mean MCC and MVD, as well as the correlation between them, were evaluated by immunohistochemical staining. Results. Statistically significant increases in mean MCC and MVD were observed between normal oral mucosa and epithelial dysplasia, normal oral mucosa and OSCC and epithelial dysplasia and OSCC (P < 0.05), but there were no statistically significant differences in MCC and MVD between low- and high-grade OSCC. Also, the Spearman's correlation coefficient showed a significant correlation between MCC and MVD (r = 0.727, P < 0.001). Conclusions. The significant correlation found between MCC and MVD is in agreement with the idea that mast cells promote tumor progression via upregulation of angiogenesis. MCC and the degree of angiogenesis can potentially be used as indicators of the evolution of SCC from epithelial dysplasia.