RESUMO
Eosinophils are suggested to have had participated in neoplastic invasion and metastasis. The aim of the present study was to evaluate eosinophilic infiltration in oral squamous cell carcinoma [OSCC] and assess its correlation with cervical lymph node metastasis and histological grading. This cross-sectional study used 20 OSCCs samples with lymph node metastasis and 20 samples without [NLM] were selected from the files of Tehran Cancer Institute. Hematoxylin-eosin stained sections were used to evaluate the presence of eosinophils in neoplastic tissues and OSCCs grading. Eosinophils were counted in 10 dense- and 10 classic-high-power-fields and graded from 0 to 4. Statistical analysis as well as Mann-Whitney-U and Kruskal-Wallis tests. The largest percentage of cases in OSCCs with and without LNM based on Eosinophil grading was 50% in grade 1 and 70% in grade 2, based on the dense-field count; and 50% in grades 1 and 0 and 70% in grade 1, when using the classic-field counting method, respectively. Eosinophilic infiltration was not significantly different between the two groups [P>0.05]. A significant difference in mean Eosinophilic count was observed among the histological grades when using the dense-field method [P=0.004], but not the classic technique [P=0.029]. Within limitations of present study it appears that the presence of Eosinophils in OSCC specimens could not be used as a clinical predictor for lymph node metastasis, however further investigation with a larger sample size is required to clarify the role of these inflammatory cells in OSCC cases