This document discusses bone marrow aspiration and biopsy procedures. Key points: - Bone marrow biopsy is important for diagnosing blood diseases and may be the only way to make a correct diagnosis. Marrow can be obtained repeatedly by needle aspiration. - The iliac crests are the preferred sites for aspiration in adults and children. The sternum should not be used in children due to risk of injury. - Proper needles, anticoagulants, and techniques are required to safely aspirate marrow and prepare diagnostic films and samples. Cell counts and differentials on aspirated marrow provide important diagnostic information.

1. BY – MALAK SALAM

2. Biopsy of the bone marrow is an
indispensable adjunct to the study of
diseases of the blood and may be the
only way in which a correct diagnosis can
be made.
Marrow can be obtained by needle aspiration.
It can be repeated many times .

4. ASPIRATION OF THE BONE MARROW
Bon marrow aspirated from :
I. Iliac spines (anterior or posterior iliac spines).
II. Sternum.
Sternum should not be used in children. In adults,
unless the needle is correctly inserted in the sternum,
there is a danger of perforating the inner cortical layer
and damaging the underlying large blood vessels and
right atrium, with serious consequences.

6. Aspiration Performing a Bone Marrow
Only needles designed for the purpose should be used for marrow
aspiration .
Clean the skin in the area with 70% alcohol.
Infiltrate the skin, subcutaneous tissue.
Pass the needle perpendicularly into the cavity of the ilium at
the centre of the oval posterior superior iliac spine or 2 cm
posterior and 2 cm inferior to the anterior superior iliac spine.
When the bone has been penetrated, remove the stilette, attach a
1 or 2 ml syringe, and suck up marrow contents for making films.

7. Ethylene diaminetetra-acetic acid (EDTA)
anticoagulant should be used when need to make
more films.
Preservative-free heparin should be used rather
than EDTA if phenotyping or cytogenetic studies
are needed.
Some material can be preserved in fixative
rather than anticoagulant for preparation of
histological sections .

8. Puncture of the Ilium
The usual sites for puncture in adults are the
posterior and, less commonly, the anterior iliac
spine, and relatively large volumes of marrow
can be aspirated from this site.

10. ASPIRATION OF THE BONE
MARROW IN CHILDREN
Iliac puncture, particularly in the region of the
posterior spine, is usually the method of choice in
children.
In an older child who is obese, can be obtained from
the anterior ilium.
In small babies, marrow can be withdrawn from the
medial aspect of the upper end of the tibia just below the
level of the tibial tubercle.

11. MARROW PUNCTURE
NEEDLES
 Needles should be stout and made of hard stainless
steel.
Should be about 7-8 cm in length, with a well-fitting
stilette.
They must be provided with an adjustable guard.
The most common reusable needles are
the Salah and Klima needles.

14. PROCESSING OF
ASPIRATED BONE
MARROW
There is little advantage in aspirating more than
0.3 ml of marrow fluid from a single site for
morphological examination because this increases
peripheral blood dilution.
It is good practice to obtain a sample of peripheral
blood from the patient at the same time as the bone
marrow so that both specimens can be examined and
stored together.

15. Preparing Films from Bone Marrow Aspirates
Make films of the aspirated marrow (3-5 cm in length)using :
1. Smooth-edged glass spreader 2 cm in width .
2. Put a drop of marrow on slide .
3. Dragged the drop by spreader leaving a trail of cells behind it .
4. Fix the films of bone marrow and stain them with Romanowsky
dyes.
5. Films can also be stained by Perls' method to demonstrate the
presence or absence of iron.
6. Overnight drying necessary to achieve optimal results with a
Perls‘ stain .

16. Concentration of marrow can be achieved by
delivering single drops of aspirate on to slides about 1
cm from one end.
This is not usually necessary for marrows that are very
cellular such as in acute and chronic myeloid leukaemia
and megaloblastic anaemia .

17. (( dry tap
It is frequently impossible to obtain any samples
of bone marrow fluid using a needle and syringe
(bone marrow aspiration ) due to marrow fibrosis
(e.g., myelofibrosis, Hairy cell leukaemia-variant
(HCL-v) ; Hodgkin's disease, lymphoma ) . The
bone marrow trephine biopsy typically shows
abnormal fibrosis of the marrow cavity .

19. Concentration of bone
marrow by centrifugation
Centrifugation can be used to concentrate the
marrow cells and to assess the relative
proportions of marrow cells, peripheral blood and
fat in aspirated material.

20. EXAMINATION OF ASPIRATED BONE
MARROW
1. Quantitative cell counts on aspirated
bone marrow:
A. The percentage of marrow in the sternum of healthy adults that
is cellular rather than fatty is 48-79%.
B. The cellularity of the marrow is affected by age.
C. The marrow undergoes slight to moderate hyperplasia in
pregnancy.
 If less than 25% of the particle is occupied by haemopoietic
cells, it is hypocellular If more than 75-80% is occupied, it is
hypercellular.

21. 2. Differential Cell Counts on Aspirated Bone Marrow
Differential counts are important because the results may
indicate prognosis and affect treatment.
It may be important to specifically count one cell type (e.g.,
blasts in acute leukaemia for assessing response to
chemotherapy).