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What type of preparation is preferred for bone marrow aspirates? a.Coverslip smears from a bone marrow fragment called a spicule b.Wedge smears made from the blood surrounding marrow fragments c.Touch preps from rolling the biopsy on a glass slide d.Smears of the biopsy made with an automated slide maker

ANS: A Coverslip smears from a bone marrow spicule are the preferred type of preparation for bone marrow aspirates. The advantage to them over slides is that less trauma occurs to the cells because they weigh so much less (relatively speaking). If done correctly, then a good monolayer of cells in the marrow can be stained and then evaluated.

A bone marrow aspirate shows copious blue granules with the Prussian blue stain. Select the correct interpretation: a.Iron overload b.Iron deficiency c.Tumor cells present d.Megakaryocytes increased

ANS: A The Prussian blue stain is an iron-specific stain (nonheme iron). When iron is in the storage form of hemosiderin, it stains blue. If copious granules are visible, then it suggests iron overload. The granules must be found in macrophage cytoplasm to rule out possible contamination of the slide or stain with iron.

The best use for bone marrow aspirate smears is: a.Counting the differential b.Determining overall cellularity c.Estimating fat-to-cell ratio d.Evaluating for focal lesions such as lymphoma

ANS: A The best use for bone marrow aspirate smear is for counting the differential. The biopsy is better for determining overall cellularity, estimating the fat-to-cell ratio, and evaluating for the possible presence of focal lesions.

What bone marrow sample is best to determine fat-to-cell ratio and overall cellularity, as well as for searching for malignant cells? a.Core biopsy b.Aspirate smears c.Peripheral blood d.Prussian blue stain

ANS: A The core biopsy is the best sample for determining overall cellularity, fat-to-cell ratio, and searching for malignant cells. It provides an intact portion of the bone marrow.

Which of the following cell types tend to be found in molded clusters in the bone marrow? a.Megakaryocytes b.Malignant cells c.Immature granulocytes d.Monocytes

ANS: B Malignant cells are often found in clusters or clumps in the bone marrow. Because they are so large, they are most easily searched for under ×10 while scanning, and they are often found at or near the edge of the coverslip (or glass slide).

6. Low power (×10) is used to count and evaluate which of the following? a.Immature neutrophils b.Megakaryocytes c.Nucleated red cells d.Plasma cells

ANS: B Megakaryocytes are the largest cell in the bone marrow, and they are easily seen and counted under *10

What is the most common site for bone marrow aspiration in an adult? a.Sternum b.Posterior iliac crest c.Tibia d.Ribs

ANS: B Most bone marrow aspirates are obtained from the posterior iliac crest in an adult. The anterior iliac crest can also be used and occasionally the ribs or vertebrae. The sternum is rich in marrow and a good specimen can be obtained from it, but it is not recommended because of the risk of puncture to the underlying heart and great vessels.

A cell is described as having an eccentric heavily stained (condensed chromatin) nucleus with blue cytoplasm. A pale perinuclear Golgi complex is noted next to the nucleus. What is this cell? a.Myelocyte b.Plasma cell c.Lymphocyte d.Myeloblast

ANS: B The description fits that of a plasma cell. These are fully differentiated B cells, whose function is to make and secrete specific immunoglobulin (antibody). Because the cytoplasm is rich in ribonucleic acid (RNA) needed for this synthesis, the cytoplasm often stains a brilliant blue.

Which of the following is least helpful in evaluating bone marrow findings? a.Differential performed on the aspirate b.Clinical findings c.Laboratory data from chemistry, immunology, and microbiology d.Examination of peripheral blood

ANS: C All clinical laboratory findings should be interpreted in light of the clinical findings (physical examination and history). It is also important to compare the bone marrow findings from the differential with what is in peripheral blood, because blood cells are derived from the bone marrow. In general, laboratory data from other sections of the laboratory are not needed; however, this is not the case when working up patients for certain diseases (e.g., protein electrophoresis in a patient suspected to have multiple myeloma).

Which of the following would be a valid indication for performing a bone marrow aspiration? a.Iron deficiency b.Folate deficiency c.Unexpected pancytopenia d.Leukocytosis from a severe infection

ANS: C An unexpected pancytopenia is a valid reason for performing a bone marrow aspiration so that the cause of the pancytopenia can be determined. Iron deficiency, folate deficiency, and leukocytosis from a severe infection can all be evaluated and diagnosed from tests performed on peripheral blood (and perhaps other tissues and/or fluids such as urine in a urinary tract infection).

Osteoblasts can be easily confused with: a.Megakaryocytes b.Osteoclasts c.Plasma cells d.Macrophages

ANS: C Osteoblasts can be easily confused with the plasma cell. They have an eccentric nucleus and blue cytoplasm; however, they do not have a well-defined Golgi complex (area of "hof"). Osteoblasts tend to be found in clusters, which is not true of normal plasma cells.

7. The myeloid-to-erythroid (M:E) ratio of a bone marrow is 1:1. Select the correct interpretation. a.Normal b.Abnormal, more fat cells than normal c.Abnormal, more white cell precursors than normal d.Abnormal, more red cell precursors than normal

ANS: D The normal M:E ratio of bone marrow is 1.5:1 to 3.3:1. A ratio of 1:1 is therefore decreased, meaning that either the number of red cell precursors has increased or the number of white cell precursors has decreased. The fat-to-cell ratio assesses the overall cellularity of the marrow and should be roughly 1:1.

For which of the following is obtaining a bone marrow core biopsy mandatory? a.Anemia is suspected. b.Leukemia is suspected. c.Megakaryocyte disorders are suspected. d.Aspirate is a dry tap

ANS: D When the aspirate is a dry tap, it is imperative that a bone marrow biopsy be obtained. This gives the hematologist and/or pathologist a way of assessing the bone marrow in the absence of an aspirate (dry tap). If the aspirate is a dry tap, then something significant is present in the marrow and the biopsy will help determine the cause.

What stain is most commonly used for bone marrow aspirates? a.Prussian blue b.New methylene blue c.Hematoxylin and eosin (H&E) d.Wright

ANS: D Wright stain is most commonly used for bone marrow aspirates. Cells stain in a similar fashion as to what is seen in peripheral blood cells, making it easy to assess their morphology.

The sites of active red marrow differ for adults and young children. Which one site is active in children but not in adults? a.Proximal end of the long bones b.Skull c.Distal ends of the long bones d.Pelvis

d. Pelvis ANS: C Red marrow is found in all the bones in children, including the distal ends of the long bones. It also initially has no fat. As the child grows and the bones lengthen and enlarge, all the available marrow space is no longer needed for blood cell production. The marrow space no longer needed becomes inactive and fatty ("yellow marrow"). It can be converted to active marrow if the demand for blood cells becomes excessive. Red marrow in an adult is composed of both blood-producing cells and fat in a roughly 1:1 ratio.