Bone Marrow Evaluation

Question 1

out of the two ways to look at bone marrow, what is better for cellularity?

Answer 1

core biopsy

Question 2

where can we collect bone marrow from small animals?

Answer 2

iliac crest
proximal femur
proximal humerus
sternum

Question 3

what is the procedure for collecting a bone marrow aspirate?

Answer 3

insert needle through stab incision
rotate needle until firmly seated in bone
remove stylet
attach syringe and aspirate

Question 4

what type of stain should you use on bone marrow aspirate slides?

Answer 4

romanovsky stain

Question 5

what type of stain is used for bone marrow biopsies?

Answer 5

H&E

Question 6

what are the seven components of a marrow evaluation?

Answer 6

cellularity
presence of megakaryocytes
myeloid:erythroid ratio
is maturation of red blood cells and white blood cells orderly and progressive?
morphologic features of precursors
other cell types or organisms
+/- iron stores

Question 7

how much of a bone marrow sample is cells and fat in normal animals?

Answer 7

25-75% cells
rest is fat

Question 8

in hypocellular marrow, what do aspirates look like?

Answer 8

blood or fatty particles

Question 9

what can cause hypocellular marrow?

Answer 9

viral infections
toxicities
immune mediated

Question 10

what does hypercellular marrow look like?

Answer 10

hyperplasia of normal cells

Question 11

what increases as megakaryocytes mature?

Answer 11

cytoplasm
eosinophilia
nuclear lobation

Question 12

how large are megakaryocytes?

Answer 12

huge

Question 13

what do erythroid cells look like?

Answer 13

intensely basophilic cytoplasm
no granules
perfectly round nucleus
dense

Question 14

how basophilic are cells in granulopoiesis?

Answer 14

lightly basophilic

Question 15

what is the range for normal myeloid:erythroid ratio for dogs and cats?

Answer 15

1:1-2:1
usually close to 1:1

Question 16

what is the range for normal myeloid:erythroid ratio for horses?

Answer 16

0.5:1-2:1

Question 17

what is the range for normal myeloid:erythroid ratio for cows?

Answer 17

0.5:1-0.6:1

Question 18

what shows that progressive maturation is occurring and normal?

Answer 18

the most mature cells are the most numerous

Question 19

what is left shifted maturation?

Answer 19

increased proportion of early precursors

Question 20

what can cause left shifted maturation?

Answer 20

increased consumption of mature cells
early regenerative response to anemia
destruction of post-mitotic precursors
a defect in cell development

Question 21

what are normal amounts of lymphocytes in dogs and cats in bone marrow?

Answer 21

dogs <10%
cats <15%

Question 22

if you see increased medium to large lymphocytes, think ___________________

Answer 22

neoplasia

Question 23

what percentage of the bone marrow should be plasma cells in dogs and cats?

Answer 23

dogs <2%
cats <5%

Question 24

if plasma cells are increased, what should you rule out?

Answer 24

antigenic stimulation
multiple myeloma

Question 25

what are some organisms that “like” the marrow?

Answer 25

Histoplasma
Leishmania

Question 26

what are some things that might point towards suspected hematologic neoplasia?

Answer 26

atypical cells in circulation
unexplained hyperglobinemia
unexplained hypercalcemia

Question 27

what is are some things that would indicate unexplained prolonged cytopenia and a bone marrow test?

Answer 27

nonregenerative anemia
neutropenia, thrombocytopenia, pancytopenia

Question 28

what is an indication for adding a core biopsy?

Answer 28

cytopenia/pancytopenia

Question 29

what do you need to rule out for cytopenia/pancytopenia?

Answer 29

myelofibrosis

Question 30

what do you need to assess with cytopenia/pancytopenia?

Answer 30

cellularity of the marrow

Question 31

what are some indications for bone marrow evaluation?

Answer 31

identification of infectious agents
suspected hematologic neoplasia
unexplained prolonged cytopenia

Question 32

why can the cellularity of an aspirate be misleading?

Answer 32

it can be aplastic marrow, but the aspirate may pick up areas of residual hematopoiesis

Question 33

why do you need a CBC to interpret a bone marrow cytology?

Answer 33

is bone marrow response appropriate?
do bone marrow findings explain abnormalities?

Question 34

what are pieces of bone marrow called?

Answer 34

spicules
flakes
particles

Question 35

what can cause hypocellular marrow?

Answer 35

viral infections
toxicities
immune mediated

Question 36

what can cause hypercellular marrow?

Answer 36

myeloproliferative disease
neoplasia

Question 37

what is hyperplasia of megakaryocytes?

Answer 37

more than 10 per 10x field

Question 38

what can cause antigenic stimulation that causes increased plasma cells?

Answer 38

immune mediated disease
ehrlichia

Question 39

how reliable are bone marrow estimates of iron?

Answer 39

not generally reliable

Question 40

what do iron pigments look like?

Answer 40

chunky, yellow-gold to brown pigment

Question 41

where is Histoplasma prominent?

Answer 41

midwest

Question 42

where is Leishmania prominent?

Answer 42

mediteranean

Question 43

what can atypical cells in circulation indicate?

Answer 43

myeloid or lymphoid leukemia
lymphoma

Question 44

what can cause unexplained hyperglobinemia?

Answer 44

mutliple myeloma
some B cell lymphomas

Question 45

what can cause unexplained hypercalcemia?

Answer 45

T cell lymphoma
multiple myeloma

Question 46

what should you rule out with neutropenia, thrombocytopenia, or pancytopenia, before looking at the bone marrow?

Answer 46

overwhelming inflammation or endotoxemia

Question 47

what happens in myelodysplasia (clonal disorder characterized by ineffective hematopoiesis)?

Answer 47

marrow normo- to hypercellular but peripheral cytopenias
dysplastic hematopoietic cells
rate of cell division may be higher than normal
cell drop-out via apoptosis higher than normal