CML

Chronic myeloid leukemia (CML) is a clonal myeloproliferative neoplasm driven by the Philadelphia chromosome, usually produced by t(9;22)(q34;q11). This rearrangement fuses BCR to ABL1, creating the BCR::ABL1 protein. Its tyrosine kinase remains switched on without normal regulatory control, so myeloid progenitors continue proliferating and resist programmed cell death. Every targeted CML therapy is intended to suppress this abnormal kinase, either at its ATP-binding site or, with asciminib, at the ABL1 myristoyl pocket. The blood picture reflects accelerated production rather than a single immature cell population. A CBC may show marked leukocytosis, thrombocytosis, basophilia, eosinophilia, and anaemia. The smear typically contains a broad spectrum of granulocytic maturation, from myeloblasts through mature neutrophils. Splenomegaly can cause left upper-quadrant fullness or early satiety; fatigue, night sweats, weight loss, and bone discomfort may accompany the disease. CML may also be discovered incidentally in a patient who feels well. A leukemoid reaction can resemble CML because both can produce neutrophilia and left shift. The distinction is not made by the WBC count alone. Infection, inflammation, medications, or malignancy can produce a reactive leukemoid picture, whereas...