Morphologic studies of the erythropoietic part of bone marrow in myeloid leukaemias.

The erythropoietic part of the bone marrow has been morphologically analyzed in 147 patients with various forms of myeloid leukaemias and in 20 healthy controls. In all the patients the percentage of basophilic erythroblasts was abnormally high and correlated to elevated mitotic indices. Megaloblastic changes were found to be relatively common in the patients. All these findings are compatible with an ineffective erythropoiesis where the normal differentiation towards more mature erythroblasts becomes in creasingly blocked during the course of the disease regardless of the type of myeloid leukaemia.