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enlargement or
other intumescences. The unanesthetized, disinfected skin is sterilized
and pulled taut over the node. A no. 1 needle on a syringe with good suc-
tion is pushed through the skin into the lymph node tissue (Fig.7). Tissue
is aspirated from several locations, changing the angle of the needle
slightly after each collection, and suction maintained while the needle is
withdrawn into the subcutis. Aspiration ceases and the syringe is removed
without suction. The biopsy harvest, which is in the needle, is extruded
onto amicroscopy slide and smeared outwithout force or pressure using a
cover glass (spreader slide). Staining is done as described previously for
blood smears.
Procedures, Assays, and Normal Values
 
 
24
1.
Skin puncture
2.
Aspiration
3.
Collecting
aspirates from
different lymph
node locations
4.
Detaching the
syringe body,
equalizing the
pressure difference
5.
Removal of the
syringe body and
cannula
6.
Pulling back the
syringe barrel
7.
Pushing the
biopsy material
onto a slide
Fig. 7 Procedure for
lymph node biopsy
Physiology and Pathophysiology of Blood Cells
 
 
25
Step-by-Step Diagnostic Sequence
On the basis of what has been said so far, the following guidelines for the
diagnostic workup of hematological changes may be formulated:
1. The first step is quantitative determinationof leukocytes (L), erythrocytes
(E) and thrombocytes (T). Because the normal range can vary so widely
in individual cases (Table 2), the following rule of thumb should be ob-
served:
A complete blood count (CBC) should be included in the baseline data,
like blood pressure.
2. All quantitative changes in L + E + T call for a careful evaluation of the
differential blood count (DBC). Since clinical findings determine
whether a DBC is indicated, it may be said that:
A differential blood count is indicated:
! By all unexplained clinical symptoms, especially
! Enlarged lymph nodes or splenomegaly
! Significant changes in any of
– Hemoglobin content or number of erythrocytes
– Leukocyte count
– Thrombocyte count
The only initial assumption here is that mononuclear cells with unseg-
mented nuclei can be distinguished from polynuclear cells. While this
nomenclaturemay not conform to ideal standards, it iswell established
and, moreover, of such practical importance as a fundamental dis-
tinguishing criterion that it is worth retaining. A marked majority of
mononuclear cells over the polynuclear segmented granulocytes is an
unambiguous early finding.
The next step has to be taken with far more care and discernment:
classifying the mononuclear cells according to their possible origin, lym-
phatic cells, monocytes, or various immature blastic elements, which
otherwise only occur in bone marrow. The aim of the images in the
Atlas section of this book is to facilitate this part of the differential diag-
nosis. To a great extent, the possible origins ofmononuclear cells can be
distinguished; however, the limits ofmorphology and the vulnerability
to artifacts are also apparent, leaving the door wide open to further
Step-by-Step Diagnostic Sequence
 
 
26
diagnostic steps (specialist morphological studies, cytochemistry,
immunocytochemistry. A predominance of mononuclear cell elements
has the same critical significance in the differential diagnosis of both
leukocytoses and leukopenias.
3. After the evaluation of the leukocytes, assessment of erythrocyte mor-
phology is a necessary part of every blood smear evaluation. It is, nat-
urally, particularly important in cases showing disturbances in the
erythrocyte count or the hemoglobin.
4. After careful consideration of the results obtained so far and the
patient's clinical record, the last step is the analysis of the cell composi-
tion of the bone marrow. Quite often, suspected diagnoses are con-
firmed through humoral tests such as electrophoresis, or through cyto-
chemical tests such as alkaline phosphatase, myeloperoxidase, non-
specific esterase, esterase, or iron tests.
Bone marrow analysis is indicated when clinical findings and blood
analysis leave doubts in the diagnostic assessment, for example in
cases of:
! Leukocytopenia
! Thrombocytopenia
! Undefined anemia
! Tricytopenia, or
! Monoclonal hypergammaglobulinemia
A bone marrow analysis may be indicated in order to evaluate the
spreading of a lymphadenoma or tumor, unless the bloodstream al-
ready shows the presence of pathological cells.
5. Bone marrow histology is also rarely indicated (even more rarely than
the bone marrow cytology). Examples of the decision-making process
between bone marrow cytology and histology (biopsy) are shown in
Table 3.
Often only histological analysis can show structural changes or focal in-
filtration of the bone marrow.
This is particularly true of the frequently fiber-rich chronic myelo-
proliferative diseases, such as polycythemia vera rubra, myelofibrosis–
osteomyelosclerosis (MF-OMS), essential thrombocythemia (ET), and
chronic myeloid leukemia (CML) as well as malignant lymphoma
without hematological involvement (Hodgkin disease or blastic non-
Hodgkin lymphoma) and tumor infiltration.
Physiology and Pathophysiology of Blood Cells
 
 
27
Table 3 Indications for a differential blood count (DBC), bonemarrow aspiration, and biopsy
Indications Procedures
All clinically unclear situations:
! Enlarged lymph nodes or spleen
! Changes in the simple CBC (penias or
cytoses)
Differential blood count (DBC)
! When a diagnosis cannot bemade based on
clinical findings and analysis of peripheral
blood differential blood analysis, cytochem-
istry, phenotyping, molecular genetics or
FISH
Bonemarrow analysis
Bonemarrow aspirate
(Morphology, phenotyp-
ing, cytogenetics, FISH,
molecular genetics)
Bonemarrow
trephine biopsy
(Morphology, immuno-
histology)
! Punctio sicca ("dry tap") not possible +
! Aplastic bonemarrow not possible +
! Suspicion of myelodysplastic syndrome + (+) (e.g. hypoplasia)
! Pancytopenia + +
! Anemia, isolated + –
! Granulocytopenia, isolated + –
! Thrombocytopenia, isolated (except ITP) + –
! Suspected ITP (+) For therapy failure –
! Suspected OMF/OMS – (BCR-ABL in peripheral
blood is sufficient)
+
! Suspected PV – (BCR-ABL in peripheral
blood is sufficient)
–
! Suspected ET – (BCR-ABL in peripheral
blood is sufficient)
+
! Suspected CML – (BCR-ABL in peripheral
blood is sufficient)
(+) Conditions for the
analysis
! CMPE (BCR-ABL negative) (+) Differential diagnoses +
! Suspected AL/AL + (+) Not in typical cases
! Suspected bonemarrowmetastases – +
! Monoclonal hypergammaglobulinemia + +
! NHL (exceptions, see below) + +
! Typical CLL + (+) Prognostic factor
! Follicular lymphoma (+) To distinguish vs
other NHL
+
! Hodgkin disease – +
Further indications for a bonemarrow analysis are:
! Unexplained hypercalcemia + +
! Inexplicable increase of bone AP – +
! Obvious, unexplained abnormalities – +
! Hyperparathyroidism – +
! Paget disease – +
! Osteomalacia – +
! Renal osteopathy – +
! Gaucher syndrome – +
+ Recommended, – not recommended, (+) conditionally recommended, ITP idiopathic thrombocytopenia,
OMF/OMS osteomyelofibrosis/osteomyelosclerosis, PV polycythemia vera, ET essential thrombocythemia,
CMPD chronic myeloproliferative disorders, AL acute leukemia, NHL non-Hodgkin lymphoma, CLL chronic
lymphocytic leukemia, FISH fluorescence in situ hybridization, AP alkaline phosphatase.
Step-by-Step Diagnostic Sequence
 
 
28
 
 
Normal Cells of the Blood and
Hematopoietic Organs
 
 
30
The Individual Cells of Hematopoiesis
Immature Red Cell Precursors: Proerythroblasts and
Basophilic Erythroblasts
Proerythroblasts are the earliest, least mature cells in the erythrocyte-
forming series (erythropoiesis). Proerythroblasts