| Which of the following statements are FALSE regarding the bone marrow BIOPSY specimen? | View Page |
| Match each of the following: | View Page |
| Preparation of Particle Smears Particle smears are also made from the unanticoagulated sample. The bone marrow particles are removed from the watchglass and placed on a coverslip. One of the following items: Pasteur pipet, capillary tube or broken end of a wooden applicator stick, may be used to transfer the particles. A second coverslip is placed over the first and the particles are crushed between the coverslips as they are pulled apart. Some practice is needed to perfect this technique. As mentioned previously, this type of preparation provides a more accurate assessment of marrow architecture and cellularity than the direct smear. Morphological detail is preserved on well made slides. The remaining sample may be added to a tube containing EDTA anticoagulant and additional smears may be made if needed. | View Page |
| Preparation of Concentrated Smears In some laboratories the anticoagulated sample is used to prepare concentrated smears. Placing the fluid in a Wintrobe tube and centrifuging it separates the sample into four layers:fat and perivascular cellsplasmabuffy layer - myeloid and nucleated erythroid cellserythrocytesThe volume of each layer is measured using the scale on the Wintrobe tube and then the percentage of each layer is calculated. Next the plasma is removed and a smear is made from the buffy coat and top of the red cell layer. Either the manual push method or cytospin technique may be used to make the smears. They may be stained with a variety of cytochemical stains. Concentrated smears are used to examine cell morphology and demonstrate the presence of abnormal cells when the marrow is hypocellular. The smears cannot be used for differential counts or evaluation of cellularity. | View Page |
| Advantages of a Biopsy Specimen Examining the biopsy allows the structure of the marrow to be viewed as it exists in the body. It provides essential diagnostic information in conditions that disrupt the normal architecture, such as metastatic carcinoma, myelofibrosis, Hodgkin's lymphoma and granuloma. A biopsy may also be used to evaluate cellularity and identify acid-fast bacteria or fungi in less time than is needed for routine culture methods. One disadvantage of the tissue sections prepared from the biopsy sample is that morphologic detail is lost. For this reason, in many cases imprint slides or smears from the aspirated sample are also examined. | View Page |
| Which of the following statements are TRUE regarding biopsy specimens? (Choose ALL of the correct answers) | View Page |
| Preparation of Direct Smears The sample in the first syringe is quickly delivered into a watchglass or onto a slide. After the technologist verifies the presence of white-gray marrow particles in the sample, push smears and/or coverslip smears from this unanticoagulated sample are made immediately. All films should be rapidly air dried. The appearance of fat as irregular holes in the films also give the assurance that marrow and not just blood has been obtained. This type of smear is referred to as a direct smear and is usually used to evaluate morphology. Although some evaluation of cellularity and M:E ratio is possible, particle smears or biopsy sections provide a more accurate representation of these factors. | View Page |
| Collection of Bone Marrow Biopsy A bone marrow biopsy involves removing a small portion of the bone marrow without destroying the architecture of the marrow. This type of biopsy is necessary when the marrow cannot be aspirated (dry tap) due to a disease process, and also provides additional information complementary to that derived from the aspirate: biopsy specimens are more accurate for assessing cellularity, and infiltrative processes, such as metastatic carcinoma, fibrosis, amyloid, and lymphoma. A biopsy specimen is processed as follows: touch preparation tissue section | View Page |
| The average bone marrow cellularity in a normal adult is: | View Page |
| Percentages of Myeloid and Erythroid Precursors The normal cellularity has been described as 50%. Therefore, about 40% of the cells would be myeloid (granulocytic) and 10% erythroid. Since cellularity and distribution may vary from one area of the marrow to another, an acceptable range for percentages of myeloid and erythroid cells would be:Myeloid cells 25-55%Erythroid cells 8-14% | View Page |
| Representative Counting Field The actual cell count is performed using the oil (100x) objective. This oil immersion field shows a representative counting field. Four granulocytes, a prorubricyte, and two rubricytes are completely visible here. 100 to 500 nucleated cells are generally counted,depending on the cellularity of the smear, and only cells completely visible in the field should be included in the count. | View Page |
| Microscopic Evaluation of Marrow Smears The microscopic examination of marrow smears can be divided into three main steps.Evaluating cellularity from the biopsy/particle smearEvaluating marrow iron from the biopsy/particle smearMorphology examination from the Romanwsky stained smears | View Page |
| Medium Power View of Biopsy This biopsy also has a cellularity of 25% and approximately 75% fat, and is therefore slightly hypocellular. | View Page |
| Select the correct answer from the choices provided. | View Page |
| Evaluating Cellularity The biopsy section or particle smears are the preparations that are preferred for the evaluation of marrow cellularity and architecture. The low power objective is used to examine the slide and compare the cellular area to the amount of fat (fat cells appear as white circles interspersed among the cellular elements). On the biopsy section the specific type of cells present are difficult to determine but the cellularity can be clearly seen. The particle smear may be used to evaluate cellularity as well as morphology. The diagnostic significance of the evaluation of cellularity, is simply to see if there are too few, too many, or sufficient cell precursors present in the bone marrow. | View Page |
| Example An example of the clear space left by a fat cell when the marrow was aspirated from the bone. Some appreciation for marrow cellularity can be obtained by comparing the cells present versus the fat spaces seen in the more cellular areas of the smear. | View Page |
| Hypercellular Bone Marrow Biopsy This is another view of the same slide showing increased cellularity and decreased fat. | View Page |
| Hypercellular Bone Marrow Biopsy A low power view of a biopsy section stained with hematoxylin eosin stain. This section is showing increased cellularity and decreased fat. This specimen is about 85% cellular. | View Page |
| Select the correct answer from the choices provided. | View Page |