Mast cells and dendritic cells in basal cell carcinoma.

Basal cell carcinoma (BCC) is a very frequent skin malignancy, with slow evolution and rare metastases. Host tissues react to tumor invasion through complex inflammatory response, comprising varied inflammatory cells. We assessed the expression of mast cells and dendritic cells in 37 archived formalin-fixed paraffin-embedded tissue samples of BCC from the oral and maxillofacial region by means of immunohistochemical (IHC) method, using the SABC (Streptavidin-Biotin Complex) indirect tristadial technique for CD117 and S100 markers. Undetermined cases were eliminated. Mast cells were found in great number at the periphery and in between the tumor islands, the positivity to CD117 being high in three cases, moderate in 11 cases and low in 16 cases. Dendritic cells were also found within the tumor stroma, but they penetrated deep inside the tumor nests. The positivity to S100 was high in one of the 20 conclusive BCC cases, moderate in seven cases and low in nine cases. Three cases were negative to S100. The characteristic location of dendritic cells prove their role as antigen-receptor cells while mast cells might play dual roles in tumor biology.