Correlation 2: Leukemia

This is a bone marrow biopsy. The bony trabeculae appear normal, but the intervening marrow is abnormal. Instead of a mixture of hematopoietic elements with fat cells, there is replacement by one cell type. Note in the picture above that the marrow is virtually filled with small blue cells--the leukemic cells--and you cannot see the normal mixture of hematopoietic elements and adipocytes.

An abnormal proliferation of white blood cells is known as leukemia. As the abnormal cells proliferate, normal hematopoietic elements, including the precursors for red blood cells, white blood cells, and platelets, are replaced. If fewer red blood cells are being produced, then the patient is said to have anemia. Persons with anemia do not have as much energy and feel tired all the time. If fewer white blood cells are being produced, then the patient is said to have leukopenia, and decreased numbers of normal white blood cells results in an increased risk for infections. If the megakaryocytes in the bone marrow are reduced, then there are fewer circulating platelets and the patient is said to have thrombocytopenia. Patients with thrombocytopenia bleed easily and may form bruises, even with minor trauma.