Comparative Study of Immune Cells Infiltration in Cutaneous Squamous Cell Carcinoma and Basal Cell Carcinoma of the Head and Neck

Background: The role of tumor-associated tissue eosinophils and mast cells in the biological behavior of tumors remains unclear. Objectives: This study was performed to compare the eosinophil and mast cell counts in the cutaneous squamous cell carcinoma (cSCC) and basal cell carcinoma (BCC) of the head and neck and to evaluate their relationship with clinicopathologic factors. Methods: The current descriptive-analytical study was conducted on the histopathologic slides of 46 BCC and 30 cSCC samples prepared by using Sirius red and Toluidine blue staining techniques for eosinophil and mast cell counts, respectively. The data were analyzed, using Pearson's correlation, t test, and ANOVA test. Results: The BCC and cSCC samples had mean eosinophil counts of 35.43 +/- 35 and 331.27 +/- 321.68 eosinophil/10 HPF, respectively, and this difference was statistically significant (P = 0.001). The levels of the mast cell infiltration were obtained as 55.33 +/- 39.90 and 63.67 +/- 40.86 in BCC and cSCC, respectively. However, this variable was not significantly different between the two groups of BCC and cSCC samples (P = 0.380). In addition, the mean eosinophil and mast cell counts were higher in cSCC grade III than in other grades; however, this difference was statistically significant only for the mast cells. Furthermore, the mean eosinophil/mast cell count in cSCC and BCC showed no significant relationship with age and gender. Conclusions: Considering the greater presence of eosinophils in cSCC than in BCC, eosinophils may be concluded to be among the factors responsible for more biologically and clinically invasive behaviors of cSCC, compared to those of BCC.