[The cells of accessory immune system].

In the Reticulo-Endothelial System (RES), named at present Accessory Immune System (AIS), two chief groups of cells can be recognized: 1--Antigen-presenting cells: Dendritic cells 2--Antigen-processing cells: Macrophages (or Histiocytic cell) True malignant Langerhans cell neoplasm has not been yet clearly demonstrated. Finally, it is important to note that marcrophages and dentritic cells are commonly observed as relative cells in numerous malignant tumors (carcinomas, sarcomas, lymphomas, etc) However, their precise role has yet to be determined.