Bone marrow, the spongy inner part of bones, produces platelets, red blood cells and white blood cells. Bone-marrow testing assesses the health of a patient's bone marrow. Sampling of bone marrow requires either a biopsy or aspiration procedure. Bone-marrow testing involves removing a sampling of cells from the bone and examining the bone marrow under a microscope.
Cancer
Leukemia, lymphoma and myeloma are cancers of the blood and bone marrow known as hematologic cancers. According to the Center for Disease Control and Prevention, there were more than 100,000 cases of blood cancer in 2005, with more than 53,000 deaths. Hematologic cancers evolve from problems with the body's stem-cell production. Physicians use bone-marrow biopsies to diagnose hematologic cancers or for staging of non-hematologic cancers by assessing whether the cancer has spread to the bone marrow.
Bone Marrow Disorders
Myelodisplastic syndromes, or bone-marrow disorders, are mostly noncancerous diseases of the blood and bone marrow. Blood cells form in healthy bone marrow, maturing over time to become white blood cells, red blood cells or platelets. White blood cells help the body fight infection, red blood cells carry oxygen to the body's tissues, and platelets are required to prevent bleeding by forming clots. In myelodisplastic syndromes, the immature blood cells never mature, leaving sufferers with too few red blood cells, white blood cells and platelets. Physicians will perform a biopsy to look for abnormal bone marrow cells.
Proliferative Disorders
Many diseases stem from an overproduction or underproduction of blood cells. These diseases stem from the bone marrow's blood cell production becoming dysfunctional in some way. Physicians use bone-marrow testing to help determine diseases like leukopenia, where the body produces too few white blood cells, and polycythemia, where the bone marrow produces too many red blood cells. Often, these illnesses stem from patient's having an autoimmune disorder, such as lupus or rheumatoid arthritis, where the body begins to attack its own healthy cells. Chemotherapy may also cause a decrease in healthy cells.
Amyloidosis
Amyloidosis is a condition that occurs when proteins known as amyloids build up in the body's organs. Bone marrow creates proteins called antibodies that protect the body from infection. After the antibodies have served their function, the body breaks them down and recycles them to create more antibodies. In patients with amyloidosis, cells in the bone marrow produce antibodies that are not broken down. The antibodies build up in the bloodstream and become deposited into the tissues as amyloid, interfering with normal organ function. Bone-marrow testing helps physicians diagnose and stage the disease.
