Color Atlas of Hematology - Practical Microscopic and Clinical ...

108Abnormalities of the White Cell SeriesTable 17ContinuedForm of myelodysplasia Blood analysis Bone marrowCMML = chronic myelomonocyticleukemiaRAEB in transformation(RAEB t)*Blasts 5%, monocytes 1000/µl,pseudo-Pelger syndromeSimilar to RAEB but 5% blastsHypercellular, blasts 20%, elevated promonocytesBlasts 20–30% (somecells contain Auerbodies)* In the WHO classification, the category RAEB t would belong to the category of acute myeloidleukemia.The new WHO classification of myelodysplastic syndromes defines thedifferences in cell morphology even more precisely than the FAB classification(Table 18).For the criteria of dysplasia, see page 106.The “5q- syndrome” is highlighted as a specific type of myelodysplasiain the WHO classification; in the FAB classification it would be a subtype ofRA and RAS. A macrocytic anemia, the 5q- syndrome manifests with normalor increased thrombocyte counts while the bone marrow containsmegakaryocytes with hyposegmented round nuclei (Fig. 37 b).Naturally, bone marrow analysis is of particular importance in the myelodysplasias.Table 18WHO classification of myelodysplastic syndromesDisease* Dysplasia** Blasts inperipheralbloodBlasts in thebone marrowRing sideroblastsin thebone marrowCytogenetics5q- syndrome Usually only E 5% 5% 15% 5q onlyRA Usually only DysE 1% 5% 15% VariableRARS Usually only DysE None 5% 15% VariableRCMD 2–3 lines Rarely 5% 15% VariableRCMD-RS 2–3 lines Rarely 5% 15% VariableRAEB-1 1–3 lines 5% 5–9% 15% VariableRAEB-2 1–3 lines 5–19% 10–19% 15% VariableCMML-1 1–3 lines 5% 10% 15% VariableCMML-2 1–3 lines 5–19% 10–19% 15% VariableMDS-U 1 cell lineage None 5% 15% Variable* RA = refractory anemia; RARS = refractory anemia with ring sideroblasts; RCMD = refractorycytopenia with more than one dysplastic cell line; RCMD-RC = refractory cytopenia with morethan one dysplastic lineage and ring sideroblasts; RAEB = refractory anemia with elevated blastcount; CMML = chronic myelomonocytic leukemia, persistent monocytosis (more than1 10 9 /l) in peripheral blood; MDS-U = MDS, unclassifiable. ** Dysplasia in granulopoiesis= Dys G, in erythropoiesis = DysE, in megakaryopoiesis = DysM, multilineage dysplasia= two cell lines affected; trilineage dysplasia (TLD) = all three lineage show dysplasia.