HEMA LEC BONE MARROW
Bone Marrow Examination and Lymphoid Indications for Bone Marrow Examination
Organs
The Bone Marrow
• Contains hematopoietic cells, stromal cells, and blood
vessels
• 3.4% to 5.9% of body weight
Main function:
• All blood formed elements ultimately develop from
this undifferentiated precursor
Bone Marrow Specimen Collection Sites
• Posterior Superior Iliac Crest
• Anterior Superior Iliac Crest
• Sternum
• Anterior Medial Surface of Tibia
• Spinous processes of vertebrae
Red Marrow
• Composed of the hematopoietic cells and
macrophages arranged in extravascular cords
Main Functions
• Production of Blood Cells
• Iron storage
• B-cell development
Bone Marrow Specimens
• Aspirate
• to identify the types and proportions of hematologic
cells and to look for morphologic variance
• Core Biopsy
• demonstrates bone marrow architecture
• important for evaluating diseases that
characteristically produce focal lesions
• also allows for morphologic evaluation of bony
spicules
Bone Marrow Aspiration and Biopsy 9. Touch preparation on slides
10. The core cylinder is then transferred to the chosen
fixative
Aspiration Procedure
• Using the same insertion point, but in a separate
location from the biopsy site
1. physician inserts a 14- to 18-gauge aspiration needle
with obturator
2. The obturator is removed, and a 10- to 20-mL syringe
is attached
3. The physician withdraws the plunger
4. The physician detaches the syringe and passes it
immediately to the medical laboratory professional
5. Preparation of smears
6. The physician may attach a second syringe to aspirate
an additional specimen
7. The needle is then withdrawn, and pressure is applied
to the wound
• **Dry Tap
Core Biopsy Procedure
1. After the incision, the physician inserts a Jamshidi
outer cannula with the obturator in place through the
skin and cortex of the bone.
2. Reciprocating rotation
3. Removal of obturator
4. Insertion of the biopsy needle through the canula
5. The physician changes the needle angle slightly
6. The biopsy needle and cannula are withdrawn from
the bone
7. The biopsy needle is placed over an ethanol-cleaned
slide
8. The stylus is pushed through to dislodge the core Preparation of the Bone Marrow Specimen
cylinder onto the slide A. Direct Aspirate Smears
• Direct transfer of freshly collected marrow specimen EXAMINING BONE MARROW ASPIRATE OR
onto 6 or more ethanol washed slides.
IMPRINT
• Preparation of wedge-smears
B. Anticoagulated Aspirate Smears
• Use of EDTA
C. Crush Smears of Bone Marrow Aspirate
• A portion of the aspirate is expelled to a petri dish or
watch glass covered with a few mL of EDTA solution and
the aspirate is spread over the surface with a sterile
applicator
• For each slide, another glass slide is placed directly
over the specimen at a right angle and presses gently to
crush the spicules
• **addition of 22% albumin
D. Concentrate (Buffy Coat) Smears
• useful when there are sparse nucleated cells in the
direct marrow aspirate smear or when the number of
nucleated cells is anticipated to be small
• compensates for hypocellular marrow and allows for
examination of large numbers of nucleated cells
without interference from fat or RBC
E. Core Biopsy Imprints (Touch Preparations)
• valuable when the specimen has clotted or there is a
dry tap
F. Histologic Sections (Cell Block) of the Core
Biopsy
• For histologic examinations
G. Marrow Core Biopsy and Aspirate Smear Stains
• Wright or Wright-Giemsa Stains
• Prussian Blue
• Immature erythroid progenitor cells
• two or three comma-shaped nucleoli, one nucleolus
touching the nuclear envelope
• tend to cluster with more mature normoblasts and
often surround histiocytes
• have centrally placed, round nuclei that stain
intensely (Poly and Ortho)
- “fried egg” appearance
EXAMINING BONE MARROW ASPIRATE OR • they are more easily recognized using the 10X
IMPRINT objective lens
Prussian Blue Iron Stain Examination • Lymphocytes are difficult to recognize
• useful for highlighting the presence of ring • Plasma cells are difficult to distinguish from
sideroblasts myelocytes in H&E stained sections
• ”clock face” nucleus
EXAMINING BONE MARROW CORE BIOPSY
SPECIMEN
• Bone marrow core biopsy specimen and imprint
examinations are essential when the aspiration
procedure yields a dry tap
• Preservation of bone marrow architecture
• To assess cellularity BONE MARROW EXAMINATION REPORTS
Lymphoid Organs • Filtration is a main function of these organs.
PRIMARY LYMPHOID ORGANS
A. BONE MARROW
• Can be considered the largest tissue of the body
• Functions as the center for antigen-independent
lymphopoiesis
Other Secondary Organs
MALT
BALT- lymphoid tissue in the lower respiratory tract
and hilar lymph nodes.
• Associated with IgA production in response to inhaled
antigens.
B. Thymus
• Small, flat, bilobed organ found in the thorax, or chest
cavity, right below the thyroid gland and overlying the
heart GALT- includes lymphoid tissue in the intestines
(Peyer’s patches) and the liver.
• In humans, it weighs an average of 30 g at birth, • Important for the development of tolerance to
reaches about 35 g at puberty, and then gradually ingested antigens.
atrophies
SECONDARY LYMPHOID ORGANS
CALT
• Lymphopoiesis, or reproduction of lymphocytes,
occurs in the secondary tissue, but this is strictly
dependent on antigenic stimulation, while formation of
lymphocytes in the bone marrow is antigen-
independent.
A. Spleen
• Largest secondary lymphoid organ
• Large discriminating filter
• Two main types of Splenic Tissue:
• Red Pulp - destroys old red blood cells
• White pulp - contains the lymphoid tissue, which is
arranged around arterioles in a periarteriolar lymphoid
sheath (PALS)
B. Lymph Nodes
• Located along lymphatic ducts and serve as central
collecting points for lymph fluid from adjacent tissues.
Liver
• serves as the major site of blood cell production during
the second trimester of fetal development
• contains Kupffer cells
• extramedullary hemato- poiesis
