Hematologic Malignancies 2 Flashcards
Diagnostic criteria in bone marrow for acute leukemias
>20% blasts in the bone marrow
Immunophenotype of blasts
CD34+
Immunophenotype myeloid blasts
CD34+ and CD33+
Immunophenotype of lymphoid blasts
Tdt+ and CD10+
Immunophenotype of mature B-lymphocytes/lymphoma
CD19+ and CD20+
Immunophenotype of mature T-lymphocytes/lymphoma
CD3+ and CD5+
Major problem with immunophenotyping for diagnosis
Many leukemias express mixed phenotypes
AML PML-RARA genotype
t(15;17)(q22;q12)
AML RUNX1-RUNX1T1 genotype
t(8;21)(q22;q22)
ALL TEL-AML1 genotype
t(12;21)(p13;q22)
AML FLT3 genotype
Cytogenet (-)
Advantages of genotyping
- Increased prognostic value
- Predicts response to therapy
- Identifies molecular targets for therapy development
3 subtyes of AML that can be diagnosed on cytogenetics only
- t(8;21)(q22;q22); RUNX1-RUNX1T1
- inv(16)(p13.1;q22); CBFB-MYH11
- t(15;17)(q22;q12); PML-RARA
AML t(15;17)(q22;q12) PML-RARA etiology
- Dominant negative blockade of normal RARA
- Inhibits granulocyte differentiation –> can be blocked with high dose of tretinoin to induce differentiation –> clinical remission
Clinical presentation of t15;17 AML PML-RARA
DIC, leukocytosis, severe thrombocytopenia –> prognosis is good is properly diagnosed
Treat with all trans retinoic acid (tretinoin)
Morphology of AML PML-RARA
- Big blasts, cleaved “bat wing” nuclei
- Cytoplasmic granules
- Auer rods in stacks
Immunophenotype of AML PML-RARA
- weak/absent CD34
- weak/absent HLA-DR
- CD13+
- CD33+
AML with Runx1-Runx1T1 etiology
Fusion protein of two transcription factors
Dominant negative repressor of myeloid maturation
Runx1 is part of heterodimeric transcription factor Core binding factor (CBF)
Clinical presentation of AML with t8;21 Runx1-Runx1T1
Younger patients/kids, symptoms of pancytopenia (fatigue, infection, bleeding)
Prognosis: Good response to chemo
Morphology of AML Runx1-Runx1T1
Some maturation to myelocytes
Occassional Auer rods
Immunophenotype of AML Runx1-Runx1T1
- CD34+
- HLA-DR+
- CD13+
- CD33 weak
AML CBFB-MYH11 etiology
- Fusion protein of transcription factor with MYH11
- Dominant negative repressor of myeloid maturation
CBFB is other part of CBF heterodimer (with Runx1)
Clinical presentation of AML with inv16 or t16;16 CBFB-MYH11
Younger patients/kids
Prognosis: Better than most if “risk adapted” therapy is used
Immunophenotype of AML with CBFB-MYH11
- CD34+, CD117+ (blasts)
- CD13+, CD33+ (granulocytes)
- CD14+, CD11b+ (monocytes)
Morphology of AML CBFB-MYH11
Mixed granulocyte-monocyte features
Increased eosinophils in blood and marrow
AML with normal cytogenetics clinical presentation
Any age group (40-50% of AML cases)
Prognosis: Depends on molecular genetics –> targeted sequencing determines treatment
Immunophenotype of AML with normal cytogenetics
- Blast markers (CD34, CD117)
- Typically CD33+
Morphology of AML with normal cytogenetics
- Undifferentiated
- Variably granulocytic
- Monocytic/monoblastic
Genes sequenced in AML with normal cytogenetic findings
- NPM1
- FLT3
- CEBPA
Sequencing predicts which therapies should be used
AML with complex karyotype clinical presentation
AML with 3 or more cytogenetic findings (translocations, monosomies, trisomies) –> usually have deletions or mutations in TP53
Any age group
Prognosis: Poor
Clinical presentation of acute lymphoblastic leukemia
- 75% of ALL cases occur in kids under 6
- Over 80% of acute leukemias in kids are ALL
80% cure rate in kids, 50% in adults
ALL B-cell subtypes that require 25% blasts in bone marrow for diagnosis
- t(9;22)(q34;q11.2) BCR-ABL1 (bad prognosis)
- t(v;11q23); MLL rearranged (bad prognosis)
- t(12;21)(p13;q22) TEL-AML1 (ETV6-RUNX1) (good prognosis)
- Hyperdiploid (>50 chromosomes) (good prognosis)