VALUATION OF MAST CELLS IN ORAL EPITHELIAL DYSPLASIA AND ORAL SQUAMOUS CELL CARCINOMA STAINING WITH TOLUIDINE BLUE STAIN: A HISTOCHEMICAL STUDY.

INTRODUCTION: Mast cells present in the connective tissue stroma release pro inflammatory and mitogenic cytokines. The mast cell in tumor act as a host immunologic anti tumor response. More than 90% of oral cancers are squamous cell carcinomas with oral epithelial dysplasia being the most common potentially malignant disorder. Mast cells play an important role in tumourigenesis. In some studies, with different granules of mast cell is closely related with angiogenesis and tumor invasion. In this study we used toluidine blue for the staining because it reveals mast cells as large, purple, oval and granulated cells. MATERIAL AND METHODS: 30 cases of oral epithelial dysplasia, 30 cases of Oral squamous cell carcinoma (OSCC) and 10 cases of Normal oral mucosa (NOM) were studied for mast cell number using toluidine blue. Mast cells were counted using an Olympus CX41 microscope fitted with an Olympus oculometer grid. Counting was carried out at ×40 by two independent observers and was done in six non overlapping fields in each slide. Mast cells were identified on the basis of the purple color attained by the granules after toluidine blue staining, but the nucleus of these cells appeared blue. RESULTS: Highly significant increase of mast cells in oral epithelial dysplasia on comparison with OSCC whereas there was only a significant increase in mast cells in OSCC on comparison with NOM. CONCLUSION: Mast cells can be used an indicator of increased angiogenesis and can help in the prediction of carcinogenesis, its progression, and also in the prognosis of the malignant lesions. [ABSTRACT FROM AUTHOR]