Bone Marrow (cont.)
What is done with the bone marrow sample?
The bone marrow core biopsy is first placed in a liquid that
keeps the cells in their natural condition (fixative solution). The
sample is then placed in a solution to soften the bone and is finally processed
like other biopsies in the tissue study (histology) laboratory. The
liquid portion of the bone marrow is spread on glass slides and
stained to make the bone marrow smears. The slides are then examined
under the microscope, usually by a specially qualified technician or
physician such as a hematologist or pathologist.
Portions of either sample may be submitted to the microbiology
laboratory for cultures. Certain conditions may require other
specialized studies such as genetic testing or cell marker
studies.
What diseases are diagnosed by bone marrow examination?
A wide variety of conditions can be diagnosed by examination
of the bone marrow. The following examples illustrate some of the
most frequent conditions, but there are many more. The presence or
absence of cancer in the bone marrow can determine what treatments
are recommended to a patient with cancer known to be elsewhere in the body. Some
cancers (leukemia, multiple myeloma) arise from cells in the marrow
so this is where the biopsy must be taken to confirm the diagnosis. A
low blood-clotting element (platelet count) in the blood
(thrombocytopenia) can be due to several causes. It is important to
establish whether or not the cells that make the platelets
(megakaryocytes) are still present in the marrow (idiopathic
thrombocytopenic purpura) or are gone (aplastic anemia). Most cases
of anemia (low red blood cells) can be diagnosed by simple blood
tests. When these tests are negative, examining the marrow can
reveal problems with the red blood cells that are uncommon
causes of anemia (sideroblastic anemia, aplastic anemia). Persistent
fevers can be caused by infections that reside in the marrow
(atypical mycobacteria, brucellosis) and a sample of the marrow may
provide the best source of culture material.