AML Flashcards
AML
AML favourable molecular genetics
- CBF Leuks - t(8;21) & inv 16
- NPM1 WITHOUT FLT3
- bZIP CEBPA
AML Intermediate risk molecular genetics
- NPM1 with FLT3
- t(9;11)
- Other cytogenetic abnormality
AML Unfavourable molecular genetics (7)
- Complex karyotype (>4 abnormality)
- Inv(3)
- t(6;9)
- KMT2A
- AML-MR
- TP53
- t(8;16)
APL genetics
t(15;17) PML::RARA
AML subtypes 2022 WHO classification
- AML with defining genetic abN
- AML MR
- AML with other defined genetic alterations
- AML defined by differentiation
- Myeloid sarcoma
Chemical exposure leading to AML or myelodysplasia
Benzene
Chlorambucil
Melphalan
(+RT)
Transient abnormal myelopoiesis (TAM) of Downs Syndrome
Blasts:
Undifferentiated/small Megs with blebbing/large megakaryoblasts.
IMPT:
Positive CD117
Variable CD34, CD36, CD42 and CD61
Aberrant expression of CD56 and CD7.
Trisomy 21
GATA1
What are the AML with defining genetic abN (6)(3)(2)
Translocations
2. PML::RARA t(15;17)
2. RUNX1::RUNX1T1 t(8;21)
3. CBFB::MYH11 inv16
4. DEK::NUP214 t(6;9)
5. RBM15::MRTFA t(1;22)
6. BCR::ABL1 t(9;22)
Rearrangements
1. KMT2A rearrangements (11q23)
2. MECOM “ (inv3)
3. NUP98 “ (11p15)
Mutations
1. NPM1 mutation
2. CEBPA mutation (biCEBPA and bZip)
What are some key morphologic
features of AML with t(8;21) ?
Blasts:
* Large
* Deep basophilic cytoplasm
* Azurophilic granules (pseudo-Chediak Higashi)
* Perinuclear hofs
* Single, long tapered Auer rods
Neutrophils:
* Variable dysplasia
* Hyposegmentation
* Abnormal cytoplasmic granulation ( homogeneous pink)
What is the immunophenotype of
AML with t(8;21) ?
- Bright CD34, HLA-DR, MPO and CD13
- Dim CD33
- Maturation asynchrony (CD34 and CD15)
- Other Key Markers positive:
- CD19, Pax-5 and CD79a
- TdT- weak expression
- CD56
What are morphological features of AML with inv(16) or t(16;16) CBFB-MYH11 ?
- Monocytic and granulocytic differentiation
- Abnormal eosinophil component (M4 Eos)
What is an unusual cytochemistry finding
in AML with inv(16) ?
- Chloracetate esterase
- normally negative in normal eosinophils
- faintly positive in the abnormal eosinophils in this AML
What is the immunophenotype of
AML with inv(16) ?
- Complex immunophenotype with multiple blast populations
-
Immature blasts
- CD34 and CD117 high expression
-
Granulocytic lineage
- CD13, CD33, CD15, CD65 and MPO
-
Monocytic lineage
- CD14, CD4, CD11b, CD11c, CD64, CD36 and lysozyme
- Other markers often positive
- CD2
What are the morphological variants of AML with t(15;17) PML::RARA ?
I. Hypergranular
* Densely packed granules and auer rods (faggot cells)
* Lower WCC
II. Microgranular
* Paucity of granules/Auer rods
* Higer WCC
* CD2 positive (association with FLT3)
What is the characteristic immunophenotype
of APL ?
- Negative : CD34, HLA-DR
- Positive: CD117, heterogenous CD13, bright CD33
- Negative for granulocytic markers: CD15
- Microgranular variant
- some CD34 positivity and CD2 positive
- CD56 - positive in 20% of cases (worse outcome)
Which variant APL translocations are
resistant to ATRA/ATO ?
- ZBTB16-RARA (11q23)
- STAT5B-RARA [t(17;17)]