[Malignant histiocytosis and immunodeficiency].

Phenotypes of the tumor cells of malignant histiocytosis (MH) were studied by using monoclonal and polyclonal antibodies in 18 autopsy cases. The tumor cells expressed different antigens in various degrees. Almost all tumor cells showed positive reaction for alpha 1-ACT; partially for alpha 1-AT, LCA and a few for lysozyme as well as LeuM1. It was most likely that the tumor cells of MH originated from the mononuclear phagocytic system (MPS). In order to reveal the relationship between MH and immunodeficiency, morphological changes of the lympho-reticular system in 18 cases of MH were studied. It was found that the lymphoid tissues, including lymph nodes, thymus, tonsil, spleen, bone marrow, lymphoid tissues of GI tract and lung etc showed severe depletion. These findings indicate that MH usually combine with immunodeficiency which is also closely related to the pathogenesis and pathological changes of MH.