Leukemia typically originates from which type of cell?

Leukemia primarily originates from immature blood cells known as "blasts." These are precursor cells that have not yet fully differentiated into mature blood cells. In the context of leukemia, the term "blasts" refers to the abnormal proliferation of these immature cells in the bone marrow, which disrupts normal hematopoiesis (the production of blood cells).

In leukemias such as acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML), there is an excessive accumulation of these blast cells, leading to significant health issues as they crowd out normal blood cells, resulting in anemia, increased risk of infection, and bleeding complications. This characteristic uncontrolled growth of blast cells is what differentiates leukemia from other types of cancers, where more differentiated cells are often the main target.

While stem cells are indeed the progenitor cells for all blood cells, and mature lymphocytes and granulocytes are types of mature white blood cells, it’s the abnormal proliferation of the immature blast cells that is fundamentally involved in the pathophysiology of leukemia.