Malignant myelosclerosis. Myeloproliferative disorder or leukemia?

Four patients with the picture of "malignant myelosclerosis" are described and the relationship of this condition to acute granulocytic leukemia is discussed. It is suggested that there is a leukemic process from the beginning, that the fibrosis of the marrow is reactive rather than neoplastic, and that the disease should not be regarded as an accelerated form of chronic (primary) myelosclerosis. The presence of excessive reticulin in the marrow in acute leukemia, especially when the patient is first seen, indicates a bad prognosis and poor response to chemotherapy. A systemic fungal infection in one patient is described.