Quantitative study of Langerhans cells in basal cell carcinoma with higher or lower potential of local aggressiveness* Estudo quantitativo das células de Langerhans em carcinomas basocelulares

BACKGROUNDS Basal cell carcinoma affects areas of the body that have been exposed to the sun, and this disorder has different clinical and histopathologic presentations. Some of these forms have a higher potential of local aggressiveness, while others have a lower potential. Langerhans cells actively participate in the skin immune system. OBJECTIVES To quantitatively evaluate the number of Langerhans cells on the epidermis of basal cell carcinoma with lower and higher potential of local aggressiveness and on adjacent normal epidermis. METHODOLOGY The authors divided the sample into two groups with 14 histological slides each: one with basal cell carcinoma with lower potential of local aggressiveness and the other with basal cell carcinoma with higher potential of local aggressiveness. Immunohistochemistry with S-100 protein was used in the identification of Langerhans Cells. Langerhans cells present in 7 microscopic fields were counted using optical microscopy (400X magnification) and Weibel's morphometric grade. The mean for each lamina was obtained. Wilcoxon's statistical test was employed. RESULTS In the group with lower potential of local aggressiveness, there was a significant increase in the number of Langerhans cells in the adjacent normal epidermis, as compared with the number of cells in the epidermis superposed to the basal cell carcinoma (pd 0.05). There was no significant statistical difference in the group with higher potential of local aggressiveness (p >0.05). CONCLUSION The higher number of Langerhans cells in the normal epidermis adjacent to the tumoral lesion with lower potential of local aggressiveness could indicate greater immunological resistance of the epidermis, thus limiting the aggressiveness of the neoplasm.