BM Evaluation Flashcards
Where is the location of red marrow at birth?
All is mostly red marrow
Where is red marrow at age 5-7?
Yellow marrow beginning to replace red
Location of red marrow in adults?
Red marrow limited to “warm” sites such as the axial skeleton and proximal portions of extremities
Where are BM samples taken from?
Prefer posterior, superior iliac crest (hips and long bones) in both children and adults
The bone marrow aspirate is the ____ portion of marrow
Liquid
Which sample do you perform a diff with?
The liquid aspirate
What purpose does obtaining a BM biopsy serve?
- Estimate cellularity
- Evaluation of architecture
- Allows us to perform immunohistochemical staining
Normal myeloid/erythroid ratio in adults
1.5/1 to 3.3/1
Normocellular formula % of cellularity
% = (100 - age) +/- 10
Comprehensive BM examination includes what?
- PB smear
- BM aspirate
- BM core biopsy/aspirate clot selection
- Ancillary studies
Ancillary studies include but not limited to…
- Immunohistochemistry
- Special stains
- Flow cytometry
- Cytogenetics
- Molecular
- Microbiology
What does the presence of spicules on a BM aspirate indicate?
Specimen was collected correctly (aka “adequate”)
Be able to identify spicules on a bone marrow?
*
When performing a diff on a BM aspirate, you perform counts and cellular morphology by looking where?
Look around edges of spicule, not against the spicule (cells may be distorted!)
Function of osteoblasts
Synthesize bone
Function of osteoclasts
Bone resorption
Characteristics of osteoblasts
- Abundant cytoplasm
- Slightly larger than plasma cell
- Clear area away from nucleus
- Often cluster together
Characteristics of osteoclasts
- Separate and distinct nuclei
- May have an uneven number of nuclei
- More easily seen in biopsies
- Increased in osteolytic bone disease
BM diff counts
- Blasts
0-3%
BM diff counts
- Promeylocytes
1-8%
BM diff counts
- Myelocytes
10-15%
BM diff counts
- Metamyelocytes
10-15%
BM diff counts
- Bands/segs (neutrophils)
12-25%
BM diff counts
- Eosinophils
1-5%
BM diff counts
- Basophils
0-1%
BM diff counts
- Monocytes
0-2%
BM diff counts
- Erythroid precursors (e.g., nRBCs)
15-27%
BM diff counts
- Lymphocytes
10-15%
BM diff counts
- Plasma cells
0-1%
When calculating the M/E ratio, what cells from the BM diff are excluded?
Lymphocytes, plasma cells, non-hematopoietic cells
Yellow marrow is composed of ____ and is not ____
Adipocytes; hematopoietic
What are the indicators for collecting a BM specimen and performing a BM analysis?
- Unexpected panocytopenia
- Presence of blastocytes in the PB
- Abnormalities in multiple cell lineages
What stains are preferred for evaluating cellularity?
Hematoxyin and eosin
What stains are helpful in examining BM for fibrosis?
Reticulin and trichome
A pathologist observes 6 megakaryocytes per low power field w/ normal granularity on the BM aspirate indicating what?
This may correlate w/ a patient who has a normal thrombocyte count
