Leukemias are derived from changes to blood cells that can occur at any time during their formation from hematopoietic stem cells by hematopoiesis. The exact point at which this transformation occurs gives rise to the specific type of leukemia, and this is why lineage identification is so important in classifying the exact condition. Leukemias can be lymphoid or myeloid – depending on the type of blood cell affected – and acute or chronic, depending on the rate of disease progression.
Lymphomas result from malignant transformations in lymphocytes. There are a number of subtypes which are based on surface markers, tumor architecture, cell morphology and differentiation, and genetic alterations. Early identification of the lymphoma subtype is important to optimize treatment.
