A comparison between the concentration of mast cells in squamous cell carcinomas of the skin and oral cavity.

UNLABELLED FUNDAMENTS: The lethality of squamous cell carcinomas (SCC) of the skin is considered low. SCC in the mouth is usually associated with poor prognosis. Current evidence suggests that mast cells in the normal tissue contribute to the tumorigenesis of SCC, probably by promoting angiogenesis. OBJECTIVE The aim of this study was to compare the concentration of mast cells in SCC of the mouth and skin and evaluate whether there is a correlation with the degree of differentiation of these tumors. MATERIAL AND METHODS Thirty cases of SCC of the skin and 34 of the mouth were investigated. Toluidine blue staining was used to identify mast cells in blocks containing the central portion of the neoplasm. RESULTS A concentration of between 0 and 10 mast cells was found in one single case of SCC of the skin and there were no cases of SCC of the mouth with concentrations of mast cells in the tumor >201. In the majority of cases of SCC of the mouth (47%; n=16), mast cell concentration was between 0 and 10, with a concentration >51 mast cells in 80% of cases of SCC of the skin. All the cases of SCC of the mouth with a concentration of mast cells between 100 and 200 and 80% of those with a concentration of 51-99 were located on the lip. The concentration of mast cells was unrelated to the degree of differentiation of the tumor. CONCLUSION The concentration of mast cells is lower in SCC of the mouth except when the tumor is located on the lip. This may reflect a lower need for cell activation in the microenvironment to improve vascularization in oral cancer.