Chronic Myeloid Leukaemia

This topic provides a detailed analysis of Chronic Myeloid Leukaemia (CML), a classic myeloproliferative neoplasm defined by a specific genetic abnormality. It is a critical subject for Zambian tertiary students in medical and biomedical programmes. The core of the topic is the pathogenesis, centred on the Philadelphia chromosome resulting from the t(9;22) translocation, which creates the BCR-ABL1 fusion gene and a constitutively active tyrosine kinase (p210). The natural history of CML is explained, progressing from a chronic phase through an accelerated phase to a terminal blast crisis. Clinical features in the chronic phase, such as splenomegaly and symptoms of hypermetabolism, are covered. The laboratory diagnosis is highlighted, demonstrating a leucoerythroblastic blood picture with a full spectrum of myeloid cells, basophilia, and the crucial confirmation via cytogenetics (Ph chromosome) or molecular studies (BCR-ABL1). The WHO criteria for distinguishing disease phases are also detailed. For university and college learners, understanding CML is paramount as it represents the paradigm for molecularly targeted cancer therapy. Mastering this topic, including its diagnosis, monitoring, and genetic basis, is essential for passing advanced haematology examinations and for participating in modern oncology care in Zambia.