THE MYELODYSPLASTIC SYNDROMES - DIAGNOSTIC-CRITERIA AND LABORATORY EVALUATION

The myelodysplastic syndromes (MDS) are a heterogeneous group of disorders of the multipotent hemopoietic stem cell, characterized by clonal proliferation with ineffective and dysplastic hemopoiesis. The usual result is one or more peripheral blood cytopenias with morphological and functional abnormalities. Diagnosis is based on morphological examination of peripheral blood and marrow smears, with the exclusion of other causes of dysplasia such as Vitamin B12 or folate deficiencies, alcohol or drugs. Bone marrow trephine histology may also be helpful whilst more specialized investigations such as cytogenetics, immunophenotyping and hemopoietic cell culture have yielded insights not only into the etiology and pathogenesis of these disorders but are finding application in increasing diagnostic precision and identification of clinically significant subgroups. This paper presents a brief discussion of the pathogenesis of the MDS followed by an overview of the diagnostic criteria, the potential usefulness of specialized investigations and the implications for disease course and prognosis.