ABSTRACT
Leukaemias comprise a heterogeneous group of clonal disorders of haemopoiesis, affecting both haemopoietic stem cells and progenitor cells within the myeloid and lymphocytic lineages. They are characterized by an excessive accumulation of abnormal leukaemia cells in the bone marrow and peripheral blood. Historically, leukaemias are often considered as ‘acute’ and ‘chronic’. Acute leukaemias are typically of rapid onset, whereas chronic leukaemias more usually appear to have evolved slowly before diagnosis; neither term refers to the severity of the disease. Myelodysplastic syndromes (MDS) are considered pre-leukaemic conditions that may progress to acute myeloid leukaemia (AML).1
