Dyserythropoiesis in the diagnosis of the myelodysplastic syndromes and other myeloid neoplasms: problem areas

An evaluation of the significance of specified dyserythropoietic features in suspected myelodysplastic syndrome (MDS) and acute myeloid leukaemia with erythroid dysplasia was made by means of evaluation of 100 electronic images of bone marrow erythroblasts from each of 20 subjects: 11 with a myeloid neoplasm, six with another condition that could cause erythroid dysplasia and three healthy controls. The evaluation was carried out independently by seven experienced haematologists/haematopathologists who were blinded to the diagnosis. The majority of the dyserythropoietic features listed in the World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues were validated, although karyorrhexis was found to be infrequent and lacking in specificity; multinuclearity and megaloblastosis were more often observed but also lacked specificity. Good majority agreement on the identification of dysplastic features was obtained. Despite this, it was demonstrated that a reliable diagnosis of MDS can often not be made on the basis of erythroid morphology alone. Interpretation of dyserythropoiesis must be carried out with full knowledge of other clinicopathological features and with a constant awareness of the other conditions that can be confused with MDS. An iron stain is essential, as cases with ring sideroblasts may otherwise not be recognised as having MDS.