Clinical and hematological aspects of chronic myelomonocytic leukemia. Study on 20 cases from a single center from...

Chronic myelomonocytic leukemia (CMML) has long been recognized as a disorder with both myelodysplastic and myeloproliferative characteristics, some patients showing clinical and morphological features resembling myelodysplastic syndrome (MDS) especially refractory anemia with excess of blasts (RAEB) with monocytosis, and others leukocytosis with neutrophilia, monocytosis and splenomegaly resembling myeloproliferative syndrome (MPS). The intrinsec differences determined at first the separation of CMML in two forms, one named "dysplastic", more similar with RAEB, and the other "proliferative", closer to chronic myeloid leukemia and then included by the recent WHO classification into a separate new created group--myelodysplastic diseases (MDD)/chronic myeloproliferative diseases (CMPD). The aim of this study was the analysis of some features of 20 cases of CMML, with emphasis on the differences between the two forms. The proliferative form of CMML differed from the dysplastic one by greater white blood cells and neutrophils counts (P < 0.001), a more important monocytosis in periferal blood (P = 0.07), and by the size and frequency of splenomegaly (P = 0.03). The sex and age of the patients, the frequency of the general symptoms, the frequency of the general symptoms and signs and that of infections, the hemoglobin and hematocrit values, the platelet counts, the percentage of myeloblasts and monocytes in bone marrow, the frequency of dysplastic traits, the percentage of reticulocytes and the modified Bournemouth prognostic index were not significantly different. These findings support the concept that CMML is a heterogeneous "overlap" syndrome between MDS and CMPD.