The nature of leukaemia, cytology, cytochemistry and the morphological classification -- Immunophenotyping and cytogenetic/molecular genetic analysis -- Acute myeloid leukaemia, integration of morphological, immunophenotypic and genetic information and the WHO classification -- Acute lymphoblastic leukaemia and acute leukaemia of ambiguous lineage -- The myelodysplastic syndromes and the myelodysplastic/myeloproliferative neoplasms -- Chronic myeloid leukaemias -- Lymphoid leukaemias of mature T, B, and natural killer cells -- Leukaemia diagnosis in resource-poor countries.