[Malignant histiocytosis (author's transl)].

According to observations in six patients and published reports, malignant histiocytosis is characterized by premature multifocal proliferation of atypical histiocytes, especially in lymph-nodes, spleen, liver, bone marrow, and lung. The diagnosis can be confirmed by electron-microscopy, and enzyme as well as immunocytochemical tests. Fever, anaemia, leukopenia (with absolute reduction in T-lymphocytes), and jaundice are frequent. Immunoglobulins are normal or polyclonally increased. Malignant histiocytosis is more like monocyte leukaemia and histiocytosis X than neoplasms of the lymphatic system.