Cll Quotes

Terminology and classification Leukaemias are traditionally classified into four main groups: • acute lymphoblastic leukaemia (ALL) • acute myeloid leukaemia (AML) • chronic lymphocytic leukaemia (CLL) • chronic myeloid leukaemia (CML). In acute leukaemia there is proliferation of primitive stem cells leading to an accumulation of blasts, predominantly in the bone marrow, which causes bone marrow failure. In chronic leukaemia the malignant clone is able to differentiate, resulting in an accumulation of more mature cells. Lymphocytic and lymphoblastic cells are those derived from the lymphoid stem cell (B cells and T cells). Myeloid refers to the other lineages, i.e. precursors of red cells, granulocytes, monocytes and platelets (see Fig. 24.2, p. 989). The diagnosis of leukaemia is usually suspected from an abnormal blood count, often a raised white count, and is confirmed by examination of the bone marrow. This includes the morphology of the abnormal cells, analysis of cell surface markers (immunophenotyping), clone-specific chromosome abnormalities and molecular changes. These results are incorporated in the World Health Organization (WHO) classification of tumours of haematopoietic and lymphoid tissues; the subclassification of acute leukaemias is shown in Box 24.47. The features in the bone marrow not only provide an accurate diagnosis but also give valuable prognostic information, allowing therapy to be tailored to the patient’s disease.