Page 92 - Haematologica Atlas of Hematologic Cytology

Scoring System those forms with with less than 2% BM blasts have a a a a a a better prognosis Moreover patients with with 1% bla- sts sts in in in in the the the PB and less than 5% blasts in in in in the the the BM are included in in in in the the the MDS MDS unclassifiable (MDS-U) subtype In order to improve diagnostic accuracy an International Working Group on on on Morphology of MDS MDS (IWGM-MDS) agreed on on on some recommendations for the the definition and enumeration of blasts (Mufti et al 2008) (see the the Chapter “Acute myeloid leukemia and related precursor neoplasms”) Table 2 orld Health rganiza on on ( ( ( H H ) ) ) 01 classi ca on on of myelodysplas c c c syndromes
(MDS) ( ( ( r r r r r er e e e e e e al al ) Dysplas c lineages
ytopenias
Peripheral blood
one marrow
MDS MDS with single lineage dysplasia (MDS-SLD)
1 1 or 2 <1% blasts No Auer rods
<5% blasts No Auer rods
<15% ring sideroblasts*
MDS MDS with mul lineage dysplasia (MDS-MLD)
2 or 3 1-3
<1% blasts No Auer rods
<5% blasts No Auer rods
<15% ring sideroblasts*
MDS MDS MDS with ring sideroblasts (MDS RS)
MDS-RS-SLD MDS-RS-MLD
1 2 or 3 1 or 2 1-3
<1% blasts No Auer rods
<1% blasts No Auer rods
<5% blasts No Auer rods
≥15% ring sideroblasts <5% blasts No Auer rods
≥15% ring sideroblasts MDS with isolated del( ) 1-3
1 or 2 <1% blasts No Auer rods
<5% blasts No Auer rods
del(5q)§
MDS MDS MDS with excess blasts (MDS ) MDS-EB-1 MDS-EB-2
1-3
1-3
1-3
1-3
2-4% blasts No Auer rods
5-19% or Auer rods
5-9%
No Auer rods
10-19% or Auer rods
MDS MDS unclassi able (MDS ) with 1% blood
blasts with SLD and pancytopenia
based on de ning cytogene c c abnormality
1-3
1 0 1-3
3 1-3
1% blasts# No Auer rods
<1% blasts No Auer rods
<1% blasts No Auer rods
<5% blasts No Auer rods
<5% blasts No Auer rods
<5% blasts No Auer rods
Refractory cytopenia of childhood
1-3
1-3
<2% blasts <5% blasts ^Peripheral blood
(PB) monocytes must be <1 x x 109/L is is present present §Alone or or or or with 1 1 1 1 1 1 addi onal abnormality
except -7 or or or or del(7q) #1% PB PB must must be be recorded on on on on on on on ≥2 separate occasions
The precise recognition and and quantification of dysplasia is is is critical for the the diagnosis and and to allow the the correct ap- plication of the WHO WHO classification in in in patients without excess blasts The WHO WHO proposal introduced a a a a a a a distinction between uni- versus multilineage dysplasia thus increasing the the prognostic value of the the classification The finding in in in in in an appropriate clinical setting of of of dysplastic alterations in in in in in at at at at least least 10% of of of the cells of of of at at at at least least one myeloid line- age is the the minimum morphological criterion for the the definition of myelodysplasia The The dysplastic morphological abnormalities to to to be taken into account are listed in in Table 4 The The cytopenia generally corresponds to the the dysplastic lineage but there may be some discordance Whereas variable degrees
*<5% if SF3B1 muta on is present ≥5% if SF3B1 muta on on 79