Histopathology of bone marrow in human chronic leukemias.

Among the patients with chronic myeloproliferative diseases including clinical symptoms of chronic myelogenous leukemia--CML--two varying compartments with substantially differing histology of hemopoiesis were found: one with predominating granulopoiesis for which the usual term of chronic granylocytic leukemia--CGL--seems inadequate. The other with proliferation of granylopoiesis and megakaryopoiesis as a neoplasia with a mixed cellularity is observed to be different in its clinical course: there are often a leukemic or subleukemic cell counts, but mostly considerable increased platelets in the peripheral blood; there is a prolonged period of latency, a higher age group, an infrequent occurrence of blastic crisis and a regular outcome into myelofibrosis. This entity of chronic megakaryocytic granulocytic myelosis--CMGM--can be seen very frequently among myeloproliferative diseases. Among a total of 718 core biopsies from the bone marrow the CMGM-patients are up to 29% compared with 21% of the typical one-cell-line disease CGL. The Ph1-chromosome may be presented in the CMGM-entity likewise.