This is a short volume which includes chapters on all areas of haematology written by people who deal with these diseases on a daily basis. The book provides descriptions of these diseases and describes the pathways involved in diagnosis and treatment. We have used full colour throughout and the book is heavily illustrated, using clinical material and text boxes to emphasise key points. The book attempts to provide a practical up-to-date guide of our current state of knowledge in this fast-moving area. We have also tried to keep jargon to a minimum so that the text does not require extensive prior knowledge. Acute leukaemia is a clonal (that is, derived from a single cell) malignant disorder affecting all age groups from infancy to old age. It is characterised by the accumulation of abnormal white blood cells in the bone marrow which replace normal marrow tissue, including haemopoietic precursor cells. This results in bone marrow failure and peripheral blood involvement.