To evaluate characteristics of myelodysplasia with hypoplastic marrow (MDH), clinical and hematological findings in 7 patients with MDH (group A) were compared with those of 23 patients diagnosed with myelodysplastic syndromes (MDS), 13 RAEB and 10 RAEB-T, according to French-American-British co-operative roup classification (group B). Cytopenia and morphological changes in 2 or 3 blood cell lines, corresponding to hematological characteristics of MDS, were observed in all patients in group A. Age distributions and gender ratios did not differ between groups A and B. As the initial symptom, anemia was recognized with a high incidence in both groups. Organomegaly such as hepatomegaly and splenomegaly were observed with nearly equal incidnece in groups A and B. The grades of anemia, leukocytopenia and thrombocytopenia were nearly equal in groups A and B. The percentage of myeloblasts in peripheral blood was higher in group B than that in group A (3.4% versus 0.6%). However, in bone marrow, it was lower in group B than that in group A (11.3% versus 16.5%). The percentage of erythroblasts in bone marrow was lower in group A than group B (17.7% versus 26.6%). Two of 3 patients in group A and 7 of 18 patients in group B showed abnormal karyotypes. The progress from initial symptoms to definite diagnosis ranged from 0.7 months to 38.4 months (mean±SD : 10.1±13.0 months) in group A, and from 0.8 months to 83.3 months (mean±SD : 10.0±18.1 months) in group B, respectively. Four of 7 patients (57%) in group A developed overt leukemia (1 case of hypoplastic leukemia, 2 cases of M2, 1 case of M5b) 1.3～14.3 months after diagnosis of MDH (mean±SD : 8.1±6.5 months), and 9 of 23 patients (39%) in group B also developed overt leukemia (6 cases of M2, 3 cases of M4) 0.5～14.5 months after diagnosis of MDS (mean±SD : 3.8±4.2 months). The median survival time (MST) from the initial symptoms tended to be longer in group A than that in group B (24.2 months versus 18.7 months). The MST from definite diagnosis also tended to be longer in group A than that in group B ( 17.4 months versus 12.1 months). These results suggest that MDH can be included into the clinical entity of MDS in respect to dysmyelopoietic disorders preceeding the onset of acute leukemia.
myelodysplasia with hypoplastic marrow