Page 53 - Williams Hematology ( PDFDrive )

28 Part I: Clinical Evaluation of the Patient Chapter 3: Examination of the Marrow 29

obese patients, the length of the needle must be sufficient to reach the removed. The needle is reinserted to the original depth at a slightly
iliac crest. The stylet should be locked into place on the hub of the needle different angle, taking care not to bend the needle, and rotated several
to prevent plugging of the needle with tissue prior to needle entry into times to free the specimen from attachments in the marrow cavity. The
the marrow cavity. Penetration of the cortex can be sensed by a slight, needle is slowly withdrawn, with the same twisting motion used during
rapid forward movement accompanied by a sudden increase in the ease insertion. The core of marrow inside the needle is removed by inserting
of advancing the needle. The stylet of the needle is removed promptly, the probe through the cutting tip and extruding the specimen through
the hub is attached to a 10- or 20-mL syringe, and approximately 0.5 to the hub of the needle. The smaller size of the cutting aperture relative
1.5 mL of fluid is aspirated. The actual aspiration of the marrow causes to the bore of the shaft of the Jamshidi instrument yields a specimen
a transient painful sensation for most patients. If additional specimen that fits loosely inside the needle and therefore is less subject to com-
volume is required, another syringe is fitted on the marrow needle, the pression, distortion, or fragmentation. The technique reliably produces
syringe and needle is rotated and an adjacent area is entered and mar- good quality biopsy specimens. Marrow biopsy should be performed
row is aspirated. The stylet may be reinserted and the marrow needle before marrow aspiration is attempted (or in a slightly different site on
slightly repositioned between aspirations. When aspiration is complete, the iliac crest) to avoid hemorrhage and distorted marrow architecture
the stylet is reinserted and the needle immediately removed from the in the biopsy core. With the availability of the biopsy needles described
bone. Pressure is applied to the skin over the aspiration site for at least 5 in this section, open (surgical) biopsies rarely are necessary but may be
minutes to minimize bruising at the site. If platelet number or function performed, for example, for diagnosis of deeply situated bone lesions or
is decreased, firm pressure should be applied for at least 10 to 15 min- at the time of a surgical procedure performed for a related indication
utes. The bloody fluid that is aspirated contains light-colored particles of (e.g., staging). An FDA-approved battery-powered drill that inserts a
marrow approximately 0.5 to 1 mm in diameter. They often are readily biopsy needle into the posterior iliac bone of adult patients provides
visible in the syringe, but may not be detected until the syringe contents more consistent and longer biopsy cores and shortens procedure time. 20
are discharged on glass slides for film preparation.
If nothing enters the syringe when aspiration is performed, the
needle may not be properly placed in the marrow cavity. The needle PREPARATION OF MARROW
can be cautiously advanced 1 to 2 mm after reinsertion of the stylet and
aspiration attempted again, or the needle can be removed from the bone SPECIMENS FOR STUDY
and reinserted in a nearby site in the anesthetized area. The thickness Several types of preparations can be made from the marrow aspirate to
of the bone must be considered when the needle is being adjusted in maximize use of the diagnostic material. Most important is the direct
the bone. Occasionally the needle must be rotated on its longitudinal film, which is made immediately from a drop of marrow suspension from
axis, or in a larger orbit, in order to loosen the marrow mechanically the unmanipulated aspirate. This preparation is the best for evaluating
before the marrow can be aspirated. If a small amount of blood has been cellular morphology and differential counts of the marrow. The particle
aspirated, a new needle should be used because of the probability of film is best for estimating marrow cellularity and megakaryocyte abun-
clotting the aspirate when it finally is obtained. Aspiration with a 50-mL dance, but morphology is obscured in the thicker parts of the film. A
syringe may succeed if use of a smaller syringe fails. Fibrotic or densely concentrate film, which is prepared from a concentrate of nucleated cells
packed leukemic marrow may resist all attempts at aspiration, in which (marrow buffy coat) achieved by centrifugation of a small volume of
case a biopsy is necessary. The most common cause of failure to obtain anticoagulated marrow, is sometimes used for detecting low-abundance
marrow is faulty positioning of the needle, and a second attempt at aspi- cells when the marrow is hypocellular. The relative proportions of cell
ration usually succeeds. A specimen preparation checklist used at the lineages are not maintained in the concentrate film preparation (often
time of procedure to verify presence of spicules, length of biopsy, and erythroid precursors are relatively enriched). In addition, this prepara-
other protocol items has been found to increase biopsy specimen length tion is subject to anticoagulant-induced changes in nuclear morphology
and decrease frequency of non-diagnostic samples. 19 or cytoplasmic vacuolization. The touch imprint from the biopsy is quite
valuable and sometimes diagnostically necessary for evaluating cellular
NEEDLE BIOPSY TECHNIQUE morphology when the aspirate is hypocellular. 21

Needle biopsy usually is performed with the Jamshidi needle, using the
same preparation as described above. The Jamshidi instrument (see MARROW FILMS
Fig. 3–1) consists of a cylindrical needle with constant bore, except After aspiration, approximately 0.5 mL of marrow is placed on a glass
for a concentrically tapered distal portion ending in a sharp, beveled slide; the rest is mixed into a tube containing ethylenediaminetetraace-
cutting tip. The stylet fits precisely inside the opening at the tapered tic acid (EDTA) solution. The marrow specimen is examined to ensure
tip, interlocks at the hub of the needle, and extends 1 to 2 mm beyond the presence of “spicules” or particles of marrow containing bony or
the end of the needle. An 11-gauge needle is most commonly used in fatty pieces, indicating successful aspiration of the marrow cavity. Direct
the United States. After the skin and the periosteum of the biopsy site marrow films are immediately prepared by transferring drops of the
are anesthetized, a 3-mm incision is made in the skin. The needle, with unanticoagulated marrow pool to fresh slides and making push films
obturator in place, is inserted into the skin incision and through the with coverslips. Sufficient films should be made for special stains. Hep-
subcutaneous tissue to the cortex of the bone. The needle is directed arinization of the aspirate is not necessary if the operator works rapidly
toward the posterior iliac spine and advanced with a twisting motion. and should be avoided because heparinization may introduce artifacts.
Penetration of the cortex is sensed by a decreased resistance to forward Formalin vapor artifact that can distort morphology can be avoided by
movement of the needle. The obturator is removed, and the needle is making sure formalin containers are not opened until aspirate smears
slowly advanced with reciprocal clockwise–counterclockwise twisting are prepared and put away.
motions around the long axis. After sufficient penetration of the bone A useful technique is preparing a thick film of marrow by dis-
(up to approximately 3 cm), the needle is rotated several times on its charging a drop or two of the aspirate on a slide, covering the aspirate
axis and withdrawn approximately 2 to 3 mm. Some needles now come with a second slide, gently pressing the slides together to express most
with a “trap” that snares the biopsy so that the needle can be directly of the blood into a gauze sponge, and then pulling the slides apart

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