[Value of hemophagocytosis in the morphological examination of the bone marrow (author's transl)].

The hemophagocytosis or the process of ingestion of blood cells by phagocytes and macrophages of the mononuclear phagocytic system (MFS), is a phenomenon that rarely could be observed in the morphological examination of the bone marrow aspirate. Occasionally it is present in certain pathologic conditions such as, malignant histiocitosis, autimmune hemolytic anemia, or some chronic inflammatory diseases. The capacity of ingestion is not an exlusive property of the phagocytes and macrophages of the MFS, so that different neoplastic cells can show it too. This study analyzes the presence of hemophagocytosis by neoplastic cells in a total of 552 bone marrow aspirates corresponding to a series of 130 patients with acute leukemia and 422 patients with diverse solid tumors. In the group of patients with acute leukemia, hemophagocytosis by blastic cells was observed in five cases with acute monocytic leukemia. In the other group with solid tumors, hemophagocytosis was present in three patients with oat-cell lung carcinomas and diffuse bone marrow metastases. The interest of the evaluation of hemophagocytosis by neoplastic cells in the morphological examination of the bone marrow is stressed, as well as it possible value in the cytological diagnosis of acute monocytic leukemia. However, in these circumstances a sdiffuse metastases by solid tumors should be always discarded, since their cytomorphological characteristics are in most cases superimposed to those of the leukemic bone marrow infiltrate.