Evaluation of Mast Cell Density in Mucoepidermoid Carcinoma and Pleomorphic Adenoma

Statement of the Problem: Mast cells are round to elliptical cells that originate from bone marrow stem cells and enter the peripheral blood. By releasing inflammatory mediators, these cells are involved in type I hypersensitivity, wound healing, defense against patho-gens, increased blood vessel formation, and destruction of the extracellular matrix. There are contradictory results regarding the role of mast cells in tumor lesions. Purpose: Considering the contradictory results and few studies on the density of mast cells in salivary tumors, the present study investigated and compared the density of mast cells in two common salivary gland tumors. Materials and Method: In the cross-sectional study after reviewing the records of patients referred to the Pathology Department of the School of Dentistry and Shahid Sadoughi Hos-pital in Yazd, 15 blocks of each of the mucoepidermoid carcinoma and pleomorphic ade-noma tumors were taken. After Giemsa staining of the samples, the average of stained cells in 10 random fields under 400× magnification was counted. The results were analyzed using statistical tests of t-test, ANOVA, Chi-square, and Mann-Whitney in SPSS ver. 22. Results: The average mast cell counts in pleomorphic adenoma (4.2) was higher than muco-epidermoid carcinoma (1.7) but there was no significant relationship (p= 0.305). In mucoep-idermoid carcinoma, the numbers of mast cells increased with increasing tumor grade (low: 0/467 moderate: 1/567 high: 2/983) and there was a significant relationship (p= 0.009). Conclusion: According to the results of the present study, it seems that the mast cells accu-mulation may be secondarily associated with inflammatory responses due to cell accumula-tion and tissue destruction by tumor cells.