BM Evaluation

Question 1

Where is the location of red marrow at birth?

Answer 1

All is mostly red marrow

Question 2

Where is red marrow at age 5-7?

Answer 2

Yellow marrow beginning to replace red

Question 3

Location of red marrow in adults?

Answer 3

Red marrow limited to “warm” sites such as the axial skeleton and proximal portions of extremities

Question 4

Where are BM samples taken from?

Answer 4

Prefer posterior, superior iliac crest (hips and long bones) in both children and adults

Question 5

The bone marrow aspirate is the ____ portion of marrow

Answer 5

Liquid

Question 6

Which sample do you perform a diff with?

Answer 6

The liquid aspirate

Question 7

What purpose does obtaining a BM biopsy serve?

Answer 7

• Estimate cellularity
• Evaluation of architecture
• Allows us to perform immunohistochemical staining

Question 8

Normal myeloid/erythroid ratio in adults

Answer 8

1.5/1 to 3.3/1

Question 9

Normocellular formula % of cellularity

Answer 9

% = (100 - age) +/- 10

Question 10

Comprehensive BM examination includes what?

Answer 10

• PB smear
• BM aspirate
• BM core biopsy/aspirate clot selection
• Ancillary studies

Question 11

Ancillary studies include but not limited to…

Answer 11

• Immunohistochemistry
• Special stains
• Flow cytometry
• Cytogenetics
• Molecular
• Microbiology

Question 12

What does the presence of spicules on a BM aspirate indicate?

Answer 12

Specimen was collected correctly (aka “adequate”)

Question 13

Be able to identify spicules on a bone marrow?

Answer 13

*

Question 14

When performing a diff on a BM aspirate, you perform counts and cellular morphology by looking where?

Answer 14

Look around edges of spicule, not against the spicule (cells may be distorted!)

Question 15

Function of osteoblasts

Answer 15

Synthesize bone

Question 16

Function of osteoclasts

Answer 16

Bone resorption

Question 17

Characteristics of osteoblasts

Answer 17

• Abundant cytoplasm
• Slightly larger than plasma cell
• Clear area away from nucleus
• Often cluster together

Question 18

Characteristics of osteoclasts

Answer 18

• Separate and distinct nuclei
• May have an uneven number of nuclei
• More easily seen in biopsies
• Increased in osteolytic bone disease

Question 19

BM diff counts

- Blasts

Answer 19

0-3%

Question 20

BM diff counts

- Promeylocytes

Answer 20

1-8%

Question 21

BM diff counts

- Myelocytes

Answer 21

10-15%

Question 22

BM diff counts

- Metamyelocytes

Answer 22

10-15%

Question 23

BM diff counts

- Bands/segs (neutrophils)

Answer 23

12-25%

Question 24

BM diff counts

- Eosinophils

Answer 24

1-5%

Question 25

BM diff counts | - Basophils

Answer 25

0-1%

Question 26

BM diff counts | - Monocytes

Answer 26

0-2%

Question 27

BM diff counts | - Erythroid precursors (e.g., nRBCs)

Answer 27

15-27%

Question 28

BM diff counts | - Lymphocytes

Answer 28

10-15%

Question 29

BM diff counts | - Plasma cells

Answer 29

0-1%

Question 30

When calculating the M/E ratio, what cells from the BM diff are excluded?

Answer 30

Lymphocytes, plasma cells, non-hematopoietic cells

Question 31

Yellow marrow is composed of ____ and is not ____

Answer 31

Adipocytes; hematopoietic

Question 32

What are the indicators for collecting a BM specimen and performing a BM analysis?

Answer 32

- Unexpected panocytopenia - Presence of blastocytes in the PB - Abnormalities in multiple cell lineages

Question 33

What stains are preferred for evaluating cellularity?

Answer 33

Hematoxyin and eosin

Question 34

What stains are helpful in examining BM for fibrosis?

Answer 34

Reticulin and trichome

Question 35

A pathologist observes 6 megakaryocytes per low power field w/ normal granularity on the BM aspirate indicating what?

Answer 35

This may correlate w/ a patient who has a normal thrombocyte count