RESUMO
BACKGROUND: Dendritic cells (DCs) play an important role in immune reactions. This study was designed to identify the distribution patterns of DCs and regulatory T-cells (Tregs) in cutaneous lymphomas. METHODS: Immunohistochemistry was used to determine langerin expression on Langerhans cells, CD11b on inflammatory DCs, CD209 and CD11c on dermal DCs, CD303 on plasmacytic DCs, and Foxp3 on Tregs in 81 cases of cutaneous lymphomas. RESULTS: Various DCs and Tregs were identified in most cutaneous lymphomas. Plasmacytic DCs, inflammatory DCs and Tregs were identified mainly in tumor areas, whereas dermal DCs were distributed both in the tumor and stromal areas. Among DCs, dermal DCs were most prominently identified in the cutaneous lymphomas not only in the tumor area but also in the stroma. The intense stromal infiltration of dermal DCs was consistent finding in T-cell lymphomas. Diffuse large B-cell lymphoma (DLBCL), not otherwise specified also showed intense stromal infiltration of dermal DCs, but stromal infiltration in DLBCL, leg type was relatively scant. CONCLUSIONS: The results suggest that all types of DCs and Tregs are involved in cutaneous lymphoma tumor immunity. Among them dermal DCs may play a dominant role.