Gettysburg Medical Center
The Clinical View
by P.E. Hoffsten, MD
14 February 2007

BONE MARROW EXAMINATIONS

            The lady came in for her annual physical examination with the only complaint being “easy fatigue and always tired”.  Surveys have shown that more than half of the general public states that they are tired.  If a survey is done in the morning, it is not quite as bad as in the afternoon.  And yet if you select out those that are tired versus those that are not, there seems to be only a tiny increase in the presence of disease among the tired population.  In other words, it doesn’t really seem that the “tired all the time” population is tired because they have disease. 

            Be that as it may, healthcare providers need to pay attention to what the patient is telling them.  And tired is a complaint that requires further inquiry.  Specifically, does tired mean that the person is falling asleep too easily or does it mean that the person is not doing things that they used to do?  Can the person still climb a flight of stairs or go grocery shopping or go out to dinner with family or friends?   This lady got my attention when she said that for the first time she shunted the annual family Christmas gathering to her daughter’s house instead of her own because she was just too tired to have the whole family over for Christmas.  Normally, she would supervise all of the cooking and the decorations.  This year, she was just too tired to do all that.  She said that she was sleeping well, perhaps too much.  She was not having fever, she didn’t hurt, she wasn’t losing weight, her appetite was well maintained, her bowel and urine habit were normal.  A complete physical examination yielded no abnormalities except slight pallor.  Then came her laboratory studies, and it was seen that her blood count showed a hematocrit of only 26%. 

            Hematocrit is medical term for the percentage of red blood cells in the volume of blood.  If a tube of blood is allowed to stand or is spun down, it is seen on the average that 42% of the total volume of a lady’s blood is red blood cells.  The remainder mostly is a slightly amber colored fluid that looks almost like beer.  This clear amber fluid contains the salt, the potassium, the sugar, the proteins, etc in the blood.  The red blood cells carry oxygen to the body.  This lady’s blood had about half the oxygen carrying capacity that she needed to function normally and it was no surprise that she would be “tired”. 

            The next step was to determine the size and shape of the red blood cells.  If they are too small, it usually means that the lady is iron deficient most likely from bleeding.  If the red blood cells are too big, it can mean that the lady is deficient on Vitamin B-12 with a disease called pernicious anemia.  This lady’s red blood cells were right in the normal range.  It didn’t appear that she had a nutritional deficiency.  Her stools were checked to see if there was blood hiding in the stools and none was found. 

            The next test done was called a reticulocyte count.  Reticulocytes are very young red blood cells and provide a measure of how fast the bone marrow is making blood.  Her reticulocyte count was very low indicating that she just wasn’t making blood very fast. 

            So now came the first fork in the road to making a diagnosis for this lady’s anemia.  In some situations medicine is relatively simple.  If a lady doesn’t have enough blood, there are only two reasons that this can happen.  First, she is losing it too fast, which this lady was not.  Or she is not making it fast enough which we have now shown was her problem.  The second fork in the road was to determine whether she was not making enough blood because she didn’t have enough raw materials, or because the bone marrow just wasn’t working.  Several more blood tests were added and it was seen that she had all the raw materials that she needed to make blood.  Thus, her problem was that the bone marrow just wasn’t making blood in a normal manner. 

            The bone marrow in an adult is most commonly contained in the so called flat bones.  These are the hips, the sternum in the middle of the chest and the skull.  To get bone marrow to examine, one has to pass a needle through the outer cortex of the bone into that spongy part in the middle where the bone marrow makes red blood cells.  In the past, doctors often used a needle to obtain bone marrow from the sternum in the middle of the chest but this has proved dangerous and is infrequently done today.  Sticking needles into a person’s skull was never a good idea and we just don’t do that.  But the hip area is easy to get to, and a safe place to obtain bone marrow for examination. 

            The person first lies on their side and the area along the crest of the hip bones is cleansed with antibacterial solutions.  The area is then numbed up with tooth deadening medicine so the person feels very little.  It is important to get tooth deadening medicine right down on the bone itself which also lets the doctor know just how deep the bone is before he puts the bone marrow needle in.  Then a needle is passed down to the bone and gently screwed thru the outer cortex until the end of the needle is into the marrow.  Gentle suction is applied to the needle and only a small amount of marrow is brought out.  Preferably this is usually just one or two ccs, about a quarter of a teaspoon.  That marrow is then spread on slides, and a clot is allowed to form for examination also.  A second core of bone marrow tissue is obtained in order to see what the marrow looks like in the bone where it lives.  Sometimes an additional amount of bone marrow is brought out for special studies if the person is suspected of having a malignancy of the marrow. 

            The bone marrow is then examined by the pathologist.  Possible diagnoses include cancer cells invading the bone marrow, or leukemias, or infections, or the problem that this lady had.  Her bone marrow was diagnosed as having “myelodysplasia”.

            Myelodysplasia is a condition in which the marrow simply isn’t working for a host of possible reasons.  Most commonly, we never find out why the marrow quits working.  Occasionally, myelodysplasia evolves into leukemia but this is not the rule.  Most commonly we just don’t know why the bone marrow quits making blood even though it has all of the nutritional starting materials that it might need. 

            This lady was then told what her diagnosis was and that she could quit wasting her money taking more and more vitamins and iron.  The iron was upsetting her stomach and she didn’t like it anyway.

            In today’s world there are treatments that may help myelodysplasia.  In this lady’s particular case, an additional blood test showed that a hormone called erythropoietin was much too low.  Medical specialists continue research trying to find out why these things happen but very frequently, we just don’t know why a hormone quits getting made and that was certainly the case in this lady.  But fortunately, the hormone erythropoietin can be provided as a shot given once a week and now six weeks after Christmas, her blood count is back up towards the normal range.  She is feeling much improved, and is bragging that she will have Christmas at her house next year.  She volunteered that she was very frightened at having a “bone marrow examination” done but did admit that it really wasn’t a whole lot different than having blood drawn out of her arm.  The preliminary workups to find out if a person needs to have a bone marrow done can all be done at your local clinics.  Checking blood counts, serum irons, Vitamin B-12 levels, erythropoietin levels, and reticulocyte counts are all very standard tests that don’t require a trip to Mayo Clinic to get done.  Remarkably sophisticated healthcare is available right in your local community.