Leukemia

The four classic leukemias become easier to recognize when two questions are asked first: 1. Which cell family is abnormal? Lymphoid disease produces ALL or CLL; myeloid disease produces AML or CML. 2. How quickly is the disease behaving? Acute leukemia is dominated by immature blasts and rapid marrow failure. Chronic leukemia expands more mature-appearing cells over months or years and may be discovered on a routine blood count. The pace explains the bedside picture. In acute leukemia, abnormal cells crowd out normal marrow early, so anemia, neutropenia, and thrombocytopenia often appear together. Chronic leukemia may initially produce a striking white-cell count with relatively preserved red-cell and platelet production. A patient can look well despite a major laboratory abnormality. This framework is a pattern-recognition tool, not a substitute for immunophenotyping and genetic testing. A high white blood cell count alone does not identify the leukemia or determine its urgency.