BY – MALAK SALAM

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 .

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.

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.

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 .

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.

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In small babies, marrow can be withdrawn from the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.

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.

PROCESSING OF

ASPIRATED BONE

MARROWThere 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.

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 .

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 .

(( 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 .

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.

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.

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).