Bone Marrow

Question 1

Bone Marrow Evaluation

Reason For

Answer 1

Peripheral blood differential counts abnormal
* persistent pancytopenia, neutropenia, or thrombocytopenia unexplained
* non-regenerative anemia
* abnormal morphology
* immature cells for no reason
* staging for neoplasia
* parasitic infections

Question 2

Bone Marrow Collection Sites

Answer 2

• Head of humerus
• Femoral head
• Can use illium, but not as common

Question 3

Aspiration Biopsy
(BM)

Answer 3

• Gathers fluid portion of bone marrow and cells
• Morphology easier to read than core biopsy
• Small amount collected and placed in dilute EDTA immediately ; smear made

Question 4

Core Biopsy

Answer 4

Core piece of bone marrow
* better sample
* greater diagnostic info
* shows tissue relationship
* better cellularity (no blood dilution)
* parasites easier to see

Question 5

Preparing Bone Marrow Smear

Answer 5

• Make immediately if not mixed with EDTA
• If mixed, make within an hour
• Samples will be thicker and have spicules (areas that contain cells)
• Use line, starfish, or compression

Question 6

Reading Bone Marrow Smears

Answer 6

• Do peripheral blood smear at same time
• Start on Low Power - gives overall cellularity
• Fat does not stain (will look like vacuoles)
• High Power gives M:E ratio

Question 7

Low Power BM Exam

Answer 7

Acellular vs Hypercellular vs Hypocellular

Look for megakaryocytes
* may be at edge of slide
* 2-10 /LPF normal
* not evenly distributed
* determines if platelets are normal or not

Question 8

Cellularity by Age
Fat vs Nucleated Cells

Answer 8

Adults
* 50% nucleated, 50% fat

Young
* 75% nucleated, 25% fat

Old
* 25% nucleated, 75% fat

Question 9

Define

BM Hypoplasia

Answer 9

Decreased number of cells
* <25% cellularity
* large areas of fat

Question 10

High Power BM Exam

Answer 10

• Percentage of erythroid and myeloid cells (M:E ratio)
• Evalutes for hemosiderin
• Describe morphology

Question 11

M:E Ratio

Answer 11

Classify 500 cells
* erythroid: 80-90% rubricytes and metarubricytes
* myeloid: 80-90% metamyelocytes, bands, and segs

Normal = 0.75:1 and 2:1 (use 1:1 for class)

Question 12

Erythroid Series
Characteristics

Answer 12

• Darker basophilic blue cytoplasm
• Circular nucleus

Question 13

Answer 13

Rubriblast
* RBC series
* most immature
* large cell with large nucleus
* multiple nucleoli
* basophilic cytoplasm
* possible mitotic figures

Question 14

Answer 14

Prorubricyte
* RBC series
* 2nd in series
* nuclear material dense and clumped
* basophilic cytoplasm

Question 15

Answer 15

Rubricyte
* RBC series
* 3rd in line
* hemoglobin being produced
* polychromatophilic
* blue/pink cytoplasm

Question 16

Answer 16

Metarubricyte
* RBC series
* also called nRBCs

Question 17

Myeloid Series

Answer 17

• Lighter lavender color cytoplasm
• Nucleus amoeboid shape

Question 18

Answer 18

Myeloblasts
* WBC steries
* most immature
* multiple nucleoli
* large nucleus
* scant cytoplasm

Question 19

Answer 19

Promyelocyte
* WBC series
* 2nd in line
* large nucleus
* nucleoli may be present
* pink/red granules noted

Question 20

Answer 20

Myelocyte
* WBC series
* 3rd in line
* greater nucleus-to-cytoplasm ratio
* granules throughout cytoplasm
* where distinction of E, N, B

Question 21

Answer 21

Metamyelocyte
* granules present in cytoplasm
* nucleus indented or “kidney-bean” shape
* nucleus smaller than before
* cytoplasm a lighter blue

Question 22

Answer 22

Megakaryocyte
* platelet series
* multiple condensed nuclei
* large size
* not counted in M:E ratio

Question 23

Classify Aspirate

Answer 23

Inflammatory Leukogram
* almost all cells are myeloid precursors and neutrophils

Question 24

Order of Maturation

Answer 24

There should be 1 blast cell for every 16-32 mature cells

Question 25

Classify Aspirate

Answer 25

Granulocytic Leukemia
* Most cells are myeloblasts or promyelocytes
* Few metarubricytes

Question 26

Classify Aspirate

Answer 26

Erythremic Myelosis
* Rubriblasts present
* Some metarubricytes
* Increased amount of other erythroid series cells

Question 27

Classify Aspirate

Answer 27

Undifferentiated Leukemia
* potential to be rubriblasts or prorubricytes
* few to none mature cells

Question 28

Classify Aspirate

Answer 28

Lymphoblastic Leukemia
* lymphoblasts present

Question 29

Classify Aspirate

Answer 29

Multiple Myeloma
* b-cells (plasma cells) that become cancerous
* lymphoblasts; plasma cells in origin
* look for perinuclear clear zones (don’t stain well)

Question 30

Identify Cell

Answer 30

Macrophages
* Present in low numbers
* Large cell with oval / indented nucleus
* Netlike nuclear chromatin
* moderate amount of cytoplasm; foamy +/- vacuoles
* Contain debris or hemosiderin

Question 31

Identify Cell

Answer 31

Hemosiderin
* iron pigment
* shows up as black granules with Romanowsky Stains
* prussian blue stain best to identify
* in macrophages and as free cells
* cats: not identifiable
* dogs: diseased or absent is significant

Question 32

Identify Cell

Answer 32

Osteoclasts
* normal in BM
* break down bone
* giant cells
* multinucleated

Question 33

Identify Cell

Answer 33

Osteoblasts
* normal in BM
* create bone

Question 34

Define

Aplastic

Answer 34

No BM developement

Question 35

Define

Dysplastic

Answer 35

Alteration in size, shape, and organization of cells
* indicates ineffective BM developement

Question 36

Define

Neoplastic

Answer 36

Abnormal developement of cells
* new or abnormal growth
* cell multiplication not controlled

Question 37

Define

Hyperplasia

Answer 37

• > 75% cellularity
• Abnormal increase due to new cell formation

Question 38

Identify Cell

Answer 38

Mast Cell
* very low number in BM
* round cells
* round central nucleus
* small purple granules fill cytoplasm - may hide nucleus