Unit 2: Bone Marrow & Stains Flashcards
Fat cell conversion (yellow marrow) occurs at what age?
- 4 years of age
- 18 years of age
-sternum, skull,
Proximal end of large bones,
vertebrae, Iliac Crest
- Spoke-like pattern of venous sinuses and cords of
hematopoietic tissue - Contains all the developing blood cell lines
Red bone marrow?
the process of replacing the active marrow by fat tissue
during development; results in restrictive active marrow sites
Retrogression
Major function of bone marrow?
production and
proliferation of blood
cells
Minor function of bone marrow?
antigen processing of
cellular and humoral
immunity
What are the three main reasons for preforming a bone marrow evaluation?
- In pts. with solid malignant tumors (Ex., lymphomas, carcinomas & sarcomas, with
possible “mets” to bone marrow) - As part of initial workup of unexplained ↑ or ↓ in RBCs, WBCs, &/or plts.
- As part of differential diagnosis workup for
infections that manifest clinically as “fevers of unknown origin ”.
Three findings used to verify bone marrow has been obtained (rather than p.b.)?
Presence of:
* Fat droplets
* Bone spicules
* Very immature hematopoietic cells
Four Preferred Locations for bone marrow tap (in order of preference)
- Posterior iliac crest (adults & children
- Sternum (adults)
- Vertebrae (in adults)
- Tibia (children < 1 yr. only)
Bone Marrow Tap” Procedure:
Less than 24 hrs before procedure, a CBC and manual differential are performed.
1. The MLS usually brings the biopsy kit to the patient’s
room.
2. Light general sedation is usually administered.
3. Area is washed with soap, antiseptic is applied, & site
is draped with sterile towels.
4. Local anesthetic (typically 2% lidocaine) is injected
into the skin over the intended site.
glass slide. The bone marrow is seen as gray particles
floating in among blood & fat droplets.“Bone Marrow Tap” Procedure:
5. Once skin is numb, local anesthetic is injected into the bone surface at the selected site.
6. Skin incision is made over the bony site, & the doctor inserts a needle into the bone marrow cavity.
7. The inner needle (obturator) is removed.
8. Vacuum is applied by pulling a syringe; 1st the bone marrow is aspirated, & then the trephine (core) biopsy is removed.
9. Smears are made from this aspirate by pouring a drop onto a glass slide. The bone marrow is seen
10. The marrow pieces are removed gently with a forceps,
placed between 2 clean glass slides, & the slides pulled in
opposite directions (“pull smears”).
11. Direct smears are made from drops left in the syringe.
12. Core biopsies are removed from the special syringe
attachment with forceps & drained of blood by placing
against sterile gauze. The core is touched lightly to 2-3 clean glass slides to make “touch preps” or “imprint films”, which are air-dried.
13. Remaining aspirate is used for cytogenetic workups, stains (Giemsa, Hematoxylin-Eosin, & Prussian Blue are standard),
What are the two needles used for bone marrow taps?
-Jamshidi
-Westerman-Jensen
needle
What are the five types of NORMAL bone marrow cells?
- Developing hematopoietic cells
- Macrophages or Histiocytes
More rarely: - Megakaryocytes
- Osteoblasts
- Osteoclasts
Normal bone marrow cells:
Developing hematopoietic cells (blasts of all types,
normally at overall ___% cellularity)
5
large cells, with
abundant cytoplasm & debris-filled vacuoles, &
irregular, “spreading” shape.
- Will be ↑ in disorders with rapid cell turnover (such as
leukemias & leukemoid reactions.)
Macrophages or Histiocytes
involved in platelet formation through endomitosis.
Megakaryocytes
part of bone marrow stroma; specialized bone matrix-__________cells.
Oval, elongated cells with eccentric nuclei & cometary-appearing cytoplasm.
Osteoblasts
Synthesizing
Is it common to see Osteoblasts and osteoclasts in bone marrow samples?
no, rare in normal adult bone marrow!
-huge (>100 u), multi-nucleated cells with ruffled border; formed from fusion of monos & macro-phages!
-Responsible for bone demineralization & resorption, thus ↑ whenever
bone destruction occurs.
Osteoclasts
What are the 7 aspects of routine bone marrow evaluation?
-Cellularity
-Differential cell count
-Type & concentration of abnormal aggregates
-Number & morphology of megakaryocytes
-Presence & degree of fibrosis (if any)
-Presence of abnormal intra- or extra-cellular material (if any).
-Presence of abnormal changes in bony ultrastructure (if any)
Where is routine bone marrow evaluation usually done?
usually done in the Pathology department, but can be done in the Hematology department of Oncology centers.
Aspects of Routine Bone Marrow Evaluation:
judged as normal, ↑ (hyperplastic) or ↓
(aplastic/hypoplastic); all evaluated on 10X.
Also reflected in ratio of fat cells to hematopoietic cells (which is normally 1:2 in adults).
Cellularity
Aspects of Routine Bone Marrow Evaluation:
Differential cell count (cellular distribution) – evaluated on 100X oil immersion. Requires counting _________ cells! Results highly variable.
-After count, M:E ratio is calculated
500-1000
Aspects of Routine Bone Marrow Evaluation:
Type & concentration of abnormal aggregates – especially estimation of storage Fe (essential in severe anemia diagnosis).
Requires____________ stain.
Prussian Blue
Aspects of Routine Bone Marrow Evaluation:
Fe stores reported as…
absent, ↓, adequate, mod. ↑ or mkd.
Infant bone marrow has little to no _____.
fat
normally M:E ratio ranges from _______, & is slightly higher in infants
2:1 - 4:1
What are the largest cells in normal bone marrow?
megakaryocytes
Bone marrow aspirate microscopic examination:
What is done on low power: 10x? (100x total magnification)?
-assess peripheral blood dilution
-find bony spicules and areas of clear cell morphology
-observe fat-to-marrow ratio, estimate cellularity
-search for tumor cells in clusters
-examine and estimate megakaryocytes
Bone marrow aspirate microscopic examination:
What is done on high power: 50x and 100x (500 and 1000x total magnification)?
-observe myelocytic and erythrocytic maturation
-distinguish abnormal distribution of cells or cell maturation stages
-perform differential count on 300 to 1000 cells
-compute myeloid-to-erythroid ratio
Normal Adult Bone Marrow Diffs in Concentrated Smears (1000-Cell Counts):
which single cell line
is most abundant in adult bone marrow? 2nd?
Neutrophils (various stages)
RBCs & their precursors
*Adult M:E ratio is range of 2:1 – 4:1
(Infant M:E ratio ranges from 5:1 – 6:1)
Myeloperoxidase (MPO or MPX) is pos in which AMLs?
M1 – M4
Myeloperoxidase (MPO or MPX) positive shows what color cytoplasmic granules?
gray-black or red-brown