[Refractory anemia with partial myeloblastic medullary infiltration. Examination of marrow biopsies (author's...

77 marrow biopsies of smouldering leukemia have been examined in triple blind fashion with the following results: the cellularity of the marrow is normal in three quarters of the cases. In one quarter the blast cells were homogenous, which confirms the diagnosis of leukemia. The frequences of the sheets of blast cells increase with the duration of the disease and reached 80% at the 20th month. In the other cases, blasts were seldom seen. Eosinophilia was frequent. Erythroblasts were always rare, in contrast to what is seen in sideroblastic anemias. The reticulin network was thickened in 25% of the cases. Thus, bone marrow biopsy may demonstrate many of the features supporting the diagnosis of smouldering leukemia.