Aetiology and pathogenesis of chronic leukaemias

Chronic myelogenous leukemia is relatively rare type of leukaemia which is characterized by the BCR-ABL gene and the Philadelphia chromosome. In contrast, chronic lymphocytic leukaemia (CLL) is relatively common and is characterised by the clonal expansion of mature CD5+/CD 19+ B lymphocytes. The aim of this chapter is to describe the pathogenesis of chronic leukaemias. Specifically, the molecular basis of chronic myelogenous and chronic lyphocytic leukaemias is considered.