Bone Marrow

Question 1

When would a bone marrow aspirate be indicated?

Answer 1

non-regenerative anemia

neutropenia

thrombocytopenia

suspected neoplasia or monoclonal gammopathy

classification of leukemia

Question 2

Where can bone marrow samples be taken?

Answer 2

Trochanteric fossa

humerus

wing of the ilium (but we don’t like this one)

Question 3

If not making slides within 20 seconds, what should the syringe be washed with before aspirating the marrow?

Answer 3

EDTA

Question 4

If a bone marrow aspirate is not possible, a core biopsy can be sent to the lab for determining cellularity. What is the limitation of this method?

Answer 4

Can’t tell differentiation of blast cells

Question 5

T/F: Push method is best for bone marrow aspirates, and to do this you need at least 0.5ml of marrow in the syringe.

Answer 5

FALSE to both

Do a pull film for marrows. Too fragile for push.

Only aspirate a few drops, otherwise you’re contaminating the sample with blood.

Question 6

What can we tell from bone marrow aspirates?

Answer 6

cellularity

presence of megakaryocytes (7-10 ok)

presence of iron stores

myeloid:erythroid ratio

orderliness/completeness of maturation

other cells (plasma cells)

abnormal cells

microorganisms (rare)

Question 7

What features make this bone marrow aspirate healthy?

Answer 7

Adequate cellularity

Variety of R/W BCs

Complete differentiation

Megakaryocyte

Question 8

A marrow aspirate in which most neutrophil precursors are very young, and there are no bands or segs, is indicative of what?

Answer 8

Consumptive disease

Question 9

How does this bone marrow aspirate look?

Answer 9

Inadequate cellularity

Question 10

Bone marrow film on a dog with anemia. What kind of anemia is on the differential?

Answer 10

Fe++ deficiency anemia

Anemia of inflammatory disease

*Iron stores present

Question 11

At what stage of maturation do the secondary granules develop and differentiate between eosinophils and basophils?

Answer 11

Myelocyte

Question 12

What is an acceptable myeloid:erythroid ratio for the bone marrow?

Answer 12

1:1 up to 3:1

Question 13

You perform a bone marrow aspirate on a patient and find that the M:E ratio is significantly increased. What are the possible causes for this?

Answer 13

Erythroid hypoplasia/aplasia

Granulocytic hyperplasia

Granulocytic leukemia (increased myeloblasts)

Question 14

A bone marrow aspirate on your patient shows a decreased M:E ratio. To determine if the shift involves the neutrophils or erythrocytes, you check the lab work, which shows a PCV of 20% (35-45), and a neutrophil count of 12,000 (3,000 - 11,000). What is the most likely cause of the change in ratio?

Answer 14

Regenerative anemia

PCV shows anemia, and there is an increase in immature RBCs. The neutrophil count is acceptable (not a decrease in neutrophil production). The shift is likely due to increased production of RBCs in response to the anemia.

*Another cause for dec M:E could be erythroid leukemia

Question 15

Cell maturation in the bone marrow should be complete and orderly, which means we should see what types of cells?

Answer 15

Polychromatophils, mature RBCs, Bands, Segs

Question 16

Plasma cells can be up to 2% of cells in the bone marrow. An increase in these cells can indicate what?

Answer 16

Presence of Ag

Multiple myeloma

Question 17

What percent of cells in the bone marrow should by lymphocytes?

Answer 17

15%

Question 18

What kind of tumors in dogs commonly metastasize to the bone marrow?

Answer 18

Mast cell tumors

Question 19

Presence of these cells in the bone marrow can indicate what pathology?

Answer 19

Osteosarcoma

*These are osteoblasts

Question 20

What are these cells?

Answer 20

Mott Cells

Plasma cells with vacuoles contining immunoglobulin that is never released.

Question 21

This bone marrow aspirate from a dog can indicate what?

Answer 21

Mast cell tumors

This is too many mast cells in the bone marrow

Question 22

Marrow aspirate from a sick and anemic dog. What is the disease?

Answer 22

IMHA

Macrophages in the bone marrow phagocytizing RBCs

Question 23

A bone marrow aspirate on a sick dog living in the Ohio River Valley shows these inclusions, with clear capsular zones around them, in the macrophages. What is the pathogen?

Answer 23

Histoplasma capsulatum

Question 24

A bone marrow aspirate on a domestic cat shows these banana shaped parasites. What are they?

Answer 24

Toxoplasma gondii

Question 25

A bone marrow aspirate on a dog with granulomatous dermatitis shows these cells, each with a round and rod shaped structure within them. What is the pathogen?

Answer 25

Leishmania

Question 26

A bone marrow aspirate on a dog shows these circular structures within the RBCs. What is the pathogen?

Answer 26

Babesia