The role of myelofibrosis in malignant leukoerythroblastosis.

This study examined the relationship of bone marrow pathology to the presence of leukoerythroblastosis in 67 patients with biopsy-proven metastatic bone marrow tumor. Both extensive tumor involvement (greater than 25% of marrow space) and severe myelofibrosis were more common in solid tumors than lymphomas. Twenty-eight of 45 solid tumor biopsies versus only 4/21 lymphoma biopsies showed both features (P less than 0.005). The presence of leukoerythroblastosis was more common in solid tumors than lymphomas and was associated with fibrosis but not tumor extent. Myelofibrosis appears to be important in the pathogenesis of leukoerythroblastosis.