2 Special cytological subtypes of acute myeloid leukaemias and myelodysplastic syndromes

Abstract

The recognition of distinct cytoimmunological subsets of pre-leukaemia and overt AML has been accomplished by morphological, immunological and ultrastructural studies. In many cases, a strong association has been documented between distinctive cytological features and specific chromosome changes. The primary genetic event underlying malignant transformation was also elucidated in a number of acute leukaemias and, as a matter of fact, assessment of these biological parameters has now an established role in the diagnostic work-up and in the monitoring of residual disease. On a more general basis, biological research in MDS is gradually clarifying the fundamental pathophysiological mechanisms of altered cell growth, and differentiation and therapeutic decision making in leukaemia is becoming increasingly dependent on the precise characterization of blast cells. Further refinement of the cytoimmunological classification of acute leukaemias and MDS is warranted in order to provide the physician with an updated framework of reference for the categorization of these heterogeneous haematological disorders and to improve the reproducibility of current morphological diagnosis among different centres (Castoldi et al, 1993).