Classification of patients with myelodysplastic syndromes according to the FAB co-operative group's proposals. Proposals for a redefinition of blast cell type II.

53 patients with the myelodysplastic syndromes (MDS) were classified according to the proposals of the FAB cooperative group 1982. 29 patients had refractory anaemia (RA), 10 refractory anaemia with excess of blasts ( RAEB ), 5 RAEB in transformation, 7 RA with ringed sideroblasts and 2 chronic myelomonocytic leukaemia ( CMML ). Counting blast cells type I and II involved no difficulties. 4 of 15 patients who developed acute myeloid leukaemia (AML) according to the FAB classification of 1976 did not fulfill the new 1982 criteria for AML. A redefinition of the blast cell type II to include a more granulated blast cells, without the characteristics of promyelocytes, would solve this problem. We conclude that a redefinition of the blast cell type II might turn out to be useful.