Morfologia normale e patologica - Home Page - Fondazione...
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Morfologia normale e patologica
Gina Zini Centro di
Ricerca
ReCAMHDpt
. Ematologia
Università
Cattolica
S. Cuore
-
Roma
EMATOLOGIA DI LABORATORIO:percorsi diagnostici e obiettivi clinici.Milano 11-12 Novembre 2010
Prerequisites for classification of myeloid neoplasms
by WHO 2008 criteria (I)
Morphologic, cytochemical
and immunophenotypic
features
of
the neoplastic cell
- to establish
lineage
and degree of maturation
-
to
decide
whether
cellular proliferation
is
cytologically
normal
or dysplastic, effective
or ineffective
Criteria should be applied to initial specimens prior to any therapy including GFs
Prerequisites for classification of myeloid neoplasms
by WHO 2008 criteria (II)
•
Blast
percentage
on PB and BM remains
fundamental
for categorizing
and for
evaluating
disease
progression
• Cytogenetic
and molecular
genetic
are required
at diagnosis
-
to
identify
specific
genetically
defined
entities-
to
establish
a baseline
to
assess
disease
progression
Morphological quantitative rules (I)
Peripheral Blood
Manual
differential
on 200 cells, WBC RBC and Plt
qualitative evaluation,
? Neutrophil
granularity? ► Well
controlled
staining
Bone Marrow aspirate
Manual
differential
on 500 nucleated
cells
► guidelines
(undiluted
samples, areas close
to
particles, multiple smears)
Cell
count
includes:- blasts
and promonocytes
- promyelocytes, myelocytes, metamyelocyes, band neutrophils, segmentedneutrophils
-
eosinophils, basophils, monocytes, mast
cells- lymphocytes- erythroid
precursors
Megakaryocytes
are not
included
BMF cell count: PB diluition
effects on cell count at different volumes
Dresch et al. J Clin Pathol 1974.
particles ?
MGKsor other
precursors ?
acceptable quality ?
BMF
•
qualitative evaluation (blasts,dysplasia,
cancer
cells…)
•
quantitative (myelogram)
and qualitative evaluation
cellularity
?
PB
highly reduced
Y Y
Y
N
increased, normal or
slightly reduced
N
N
•
From the FAB 1976 to
the WHO 2008 the blast
percentage
remains
a major factor
in diagnosis, subclassification
and prognosis
•
The definition
of a blast
cell
is
still
based
on that
one
proposed
in 1976 by
the FAB group.
• It
is
unclear
whether
it
has
been
applied
in the same
manner
worldwide.
•
Since
the WHO has
changed
the definition
of AML (minimum criterion
is 20% blasts) and since
RAEB has
been
diveded
into
2 groups
(5 to
9%
and 10 to
19% of blasts, respectiely) it
has
become
clear
that
the definition
of blasts
of granulocyte
lineage
should
be
more precise.
Flow cytometry determination should not be used as substitute (diluition, not all blasts are CD34+)
Morphological quantitative rules (II)
Bl
≥
20% Bl
≥
20%
Bl
< 20%
Blasts
ANC and NEC
Myelogram
1
Granulocytic
series 50%
Blasts
20%Erythroid
series
25%
Lymphocytes
5%
L/E=
2,8
Blasts/ ANC: 20%
DGN: AML
Myelogram
2
Granulocytic
series
25%Blasts
5%
Erythroid
series
65%Lymphocytes
5%
L/E=
0,46
Blasts
/NEC: 5 x100/30= 16,6%
DGN: AREB II
* ANC: all nucleated cells* NEC: non erythroid cells. Lymphocytes and plasmacells are excluded too
Myelogram
3
Granulocytic
series
10%Blasts
4%
Erythroid
series
80%Lymphocytes
6%
L/E=
0,17
Blasts
/NEC: 4 x100/14= 28,57%
DGN: AML
WHO 2008 Diagnostic
algorythm
WHO 2008 MDS Classification
-
Adults
WHO 2008 MDS Classification
-
Childhood
Simultaneous
proliferation
and apoptosis
of hematopoietic
cells
Additional
category: Refractory Cytopenia
of Childhood
(RCC)
ChildrenUsually
hypocellular
BM
<2% blasts
in PB<5% blasts
in BM
Persisten
cytopenia(s) with
dysplasia
WHO 2008: Acute Leukemia and Related Precursors Neoplasms
AML with
myelodisplasia-related
changes
Dysplasia must be present in
at least
50% of the cells
at
least
in 2 BM cell
lines.
What is a Ring Sideroblast?•
An erythroblast with siderotic
granules
–
5 or more [Juneja
1983] –
10 or more [Cazzola
1988, Brunning
(WHO) 2001]
•
Covering a certain proportion of the nuclear outline–
A third or more [Juneja
1983, Cazzola
1988, Brunning
2001]•
What the 2008 WHO
classification will advise
–
5 or more siderotic
granules–
Covering a third or more of the nuclear circumference
•
Myeloblasts, monoblasts
and megacaryoblasts
should
be included.
•
Erythroblats
should
be
considered
“blast
equivalent
“
only
in the Pure acute erythroid
leukemia.
•
Promonocytes
are considered
“monoblast
equivalent
“
when the requisite percentage
is
tallied
for
the diagnosis
of acute
monoblastic, acute monocytic
and acute myelomonocytic leukemia.
•
In acute promyelocytic
leukemia the “blast equivalent “
is the abnormal promyelocyte.
• Small dysplastic MGK and microMGK
are not blasts.
WHO 2008: What is a Blast Cell?
Myeloblasts