Acute Myeloid Leukaemia Flashcards
List the different categories and prognosis used in the molecular classification of AML
1) AML with recurrent cytogenetic abnormalities
2) AML with mutated NPM1
- Generally good risk, depends upon co-mutations
- FLT3 ITD + DNMT3A= poor risk
- NRAS + DNMT3A= good risk (unexpectedly!)
3) Chromatin-splicing group
- Chromatin: ASXL1, EZH2, BCOR, STAG2
- Splicing: SRSF2, SF3B1, U2AF1, ZRSF2
- Poor risk
4) AML with TP53, chromosomal aneuploidies and complex karyotype
- Includes isolated chromosomal arm losses
- Poor risk
5) IDH2 R172
- Good risk
6) AML; no driver mutations present
- Approximately 4% have no driver mutations on NGS
7) AML; drivers but not class defining
- DNMT3A, TET2, IDH1, FLT3, NRAS
List the early granulocytic markers used in flow cytometry
CD117
CD13
CD33
Cytoplasmic MPO
List the granulocytic maturation markers
CD15
CD65
List the monocytic markers
CD4, CD14, CD11c, CD36, CD64, CD68, lysosome, nonspecific esterase
List the megakaryocytic markers
CD41, CD42, CD61
List the erythroid markers
CD235a (glycophorin A), haemoglobin A, E-cadherin
What is the definition of acute myelomonocytic leukaemia?
Neutrophils and their precursors constitute ≥20% of bone marrow cells AND monocytes and their precursors constitute ≥20% of bone marrow cells.
What is the definition of acute monocytic leukaemia?
AML in which ≥80% of the leukaemic cells are of the monocytic lineage (cells are mostly promonocytes and monocytes)
What is the definition of acute monoblastic leukaemia?
AML in which ≥80% of the leukaemic cells are of monocytic lineage AND ≥80% of the leukaemic cells are monoblasts (cells are mostly monoblasts)
What is the definition of pure erythroid leukaemia?
> 80% of the bone marrow cells are erythroid with ≥30% proerythroblasts.
Myeloid blasts should not be increased.
What is the definition of acute megakaryoblastic leukaemia?
AML where ≥50% of blasts are of megakaryocyte lineage.
What are the immunophenotypic features of acute erythroid leukaemia?
PAS usually positive
CD34 and HLA-DR often negative
CD117 often positive
Glycophorin A (CD235a), Haemoglobin A and the less lineage specific marker CD71a usually positive but can be negative in early, undifferentiated blasts
E-cadherin positive in most cases (present in immature erythroid cells)
What are the immunophenotypic features of acute megakaryocytic leukaemia and what are some of the disease/ cytogenetic associations seen with this type of leukaemia?
PAS may be positive CD45 negative. CD34 and HLA-DR negative. Variable expression of CD13 and CD33 ≥1 megakaryocytic markers: CD41, CD61 or CD42b.
Genetic associations: AML in patients with Down syndrome, t(1;22), AML with inv(3) or t(3;3), AML with MRC
What are the features of acute basophilic leukaemia?
- AML in which the primary differentiation is to basophils.
- Characteristic metachromic staining with toluidine blue.
- MPO negative
- PAS may be positive
- Acid phosphatase positive
- May express CD34 and HLA-DR.
- CD117 negative.
- Myeloid maturation markers CD13 and CD33 usually positive.
- Monocytic markers negative with the exception of CD11b.
What is acute panmyelosis with fibrosis
Panmyeloid proliferation with blasts ≥20% and accompanying fibrosis of the bone marrow.
Characterised by abnormal, dysplastic megakaryocytes and an acute clinical illness with fevers and bone pain.
- MPO usually negative
- Express CD34 with ≥1 myeloid associated antigen: CD117, CD13, CD33.
- Complex karyotype and abnormalities in chromosome 5 and/ or 7 are common
- Poor prognosis
What five mutations are associated with an especially poor prognosis in AML?
DNMT3A TP53 ASXL1 SRSF2 RUNX1