Acute Lukemias Flashcards
What is a Leukemia?
Group of heterogenous disorders characterized by the accumulation of malignant white cells in bone marrow and blood.
How do these cells cause morbidity and mortality?
- Bone Marrow failure leads to:
- Anemia
- Neutropenia
- Thrombocytopenia - Infiltration of organs
- Liver
- Spleen
- Lymph Nodes
- Meninges
- Brain
- Skin
- testes
What are the classification levels for AML?
FAB M0-M7
What are the classification levels for ALL?
FAB: L1-L3
In what population is ALL most common?
Most common in children 3-7 falling off by 10 years and then secondary rise in risk by age 40.
In what age group is AML most common?
AML occurs is all age groups.
- Is the most common form of acute Leukemia in adults.
- Increasingly common with age
What are the 2 types of AML?
Primary and Secondary.
Which is more difficult to treat?
Secondary, which usually arises from MDS etc
Etiology of Acute Leukemias
- Idiopathic (Largest cause)
- Prior Chemotherapy
- Prior Radiotherapy
- Chemical exposure especially Benzene
- Myelodysplastic syndromes
- Myeloproliferative diseases
- Down’s syndrome
- Fragile chromosome syndromes (Fanconi’s anemia)
- Aplastic anemia and PNH
What is the pathogenesis of acute leukemia?
- Aggressive diseases (will rapidly cause death if not treated)
- Malignant transformation occurs in hematopoetic stem cells or early progenitors
- Genetic damage that causes increased rate of proliferation, reduced apoptosis, block in cellular differentiation
These events result in accumulation of blasts.
What is the definition of Acute Leukemia?
WHO defines Acute Leukemia as having over 20% blasts cells in the blood or BM.
What is a secondary defiition of Acute Leukemia?
Diagnosis of specific leukemia associated cytogenetic or molecular genetic abnormalities even if blast count is <20%
What is the difference between ALL and AML?
AML refers to blasts from the myeloid line and ALL refers to blasts from the Lymphoid line.
How is the lineage of these “BLASTS” determined?
Immunophenotyping to determine pattern of antigen expression on BLASTS surface.
What is the current method for Leukemia diagnosis?
Molecular Genetics.
What is the FAB classification of AML?
M0-Undifferentiated M1-Without Maturation M2-With granulocytic maturation M3-Acute promyelocytic M4-Granulocytic and Monocytic maturation M5-Monoblastic (M5a) or monocytic (M5b) M6-erythroleukemia M7-megakaryocytic
What is the key morphologic difference between ALL and AML?
Presence of Auer rods with AML.
What are other methods of differential diagnosis?
Genetic analysis
What are the most useful immunological markers in AML?
MPO, CD33, CD13, HLA-DR
What are the most useful immunological markers in ALL?
TdT, CD10, CD19, CD20
What is the translocation responsible for APML (M3)?
t(15;17)