B-ALL Flashcards
B-ALL Morphologically and IMPT defined
>20% Blasts
Pro-B: CD19, CD22, CD79a and TdT
Common-B: CD10
Pre-B: cIgM
Transitional-B: HC but not LC
Features of B-ALL with high hyperdiploidy
- 51-56 chromosomes
- Kids
- Mutation in RTK-Ras pathway
- Good Prognosis
Features of B-ALL with hypodiploidy
- < 43 chromosomes
- Teens and adults
- TP53 mutations
- Poor Prognosis
Modalities for detection of aneuploidy
I. Karyotype
* Metaphase
* 20 cells cultured
* 2 cells for abN and 3 cells for loss of chromosome
II. FISH
* Interphase
III. Flow
* DNA Index (DI)
* Ratio of MFI Blasts : Normal cells
* < 0.9 Hypodiploidy and > 1.16 Hyperdipoidy
Features of B-ALL with BCR::ABL1
- t(9;22) p190
- Increases with age
- Myeloid Markers CD13, CD33 (and CD25)
- Poor prognosis
Features of B-ALL with KMT2A
- 11q23 (+++ fusion partners)
- Infants
- > WCC and CNS involvement
- Positive for CD19, Negative for CD10, TdT and CD24
- Myeloid markers CD15 and CD65
- Poor prognosis
Features of B-ALL with TCF::PBX1
- t(1;19)
- Kids
- Pre-B: CD19, CD10 and cIgM
- Bright CD9 and Dim to negative CD34
- Intermediate risk
Features of B-ALL with TCF3::HLF
- t(19;17)
- Rare
- Kids
- Poor prognosis
Features of B-ALL with IgH::IL3
- t(5;14)
- Kids and teens
- Eosinophils with low/no PB blasts
- Common-B: CD19 and CD10
- Myeloid markers CD13, CD33 and CD123
Features of B-ALL with ETV6::RUNX1
- t(12;21)
- kids
- Positive CD9, CD20, CD66c and CD17
- Myeloid Markers CD13 and CD33
- Good prognosis
Features of B-ALL with iAMP21
- Kids
- Low WCC
- Poor prognosis (High relapse rate)
Features of B-ALL with BCR::ABL1-like
- Mutations consituitively activate JAK/STAT
- > with age and DS
- High WCC
- Poor prognosis
Features of B-ALL with ETV6::RUNX1-like
- Kids
- CD27 Positivity
DDx for B-ALL with Myeloid Markers
- BCR::ABL1 (CD13,CD33 and CD25)
- KMT2A (CD15 and CD65)
- IgH::IL3/t(5;14) (CD13, CD33 and CD123)
- ETV6::RUNX1/t(12;21) (CD13, CD33)