Chronic myeloid leukaemia is a malignant clonal proliferation of an abnormal haemopoietic stem cell. Over a period of many months the cell line expands, producing myeloid cell types. Normal haemopoiesis is gradually replaced.
Chronic myeloid leukaemia accounts for 20% of all leukaemias. It occurs mainly in middle aged and elderly people and is characterised by marked leucocytosis, a left shifted myeloid series and in 95% of patients, the Philadelphia chromosome.
CML develops insidiously. Initial symptoms are often nonspecific and due to anaemia or hypermetabolism. Weakness, weight loss and fatigue are common. Massive splenomegaly is characteristic and may cause left hypochondral pain.
The condition usually remains stable for years and then transforms to a more overtly malignant disease. It is invariably fatal but patients may enjoy a near normal life during the chronic phase.
Allogeneic bone marrow transplantation, the only curative treatment for CML, is associated with substantial morbidity and mortality and is limited to patients for whom a suitable donor is available.
Last reviewed 01/2018