AML Flashcards
t(8:21)
Runx1-Runx1T1
t(8:21)
- -fusion protein of two transcription factors
- -5% of AML cases
- -Class II mutant (dominant repressor of myeloid maturation)
t(8:21)…Clinical presentation
younger pts/ kids
t(8:21)…Morphology
- -Some maturation to myelocytes
- -Occasional crystallization of granule contents (“Auer rods”)
t(8:21)…Immunophenotyping
CD34+
HLA-DR+
CD13+
CD33 weak
t(8:21)…Prognosis
Good Response to chemo
t(15;17)(q22;q12)
PML-RARA
t(15;17)
- -Fusion of PML (transcription factor) with RARA (transcription factor - retinoic acid receptor)
- -5-8% of AML cases
t(15;17)
Previously called AML-M3 or acute promyelocytic leukemia!!! (APL)
t(15;17)
- -Dominant negative blockade of normal RARA
- -Inhibits Granulocyte differentiation (Class II mutation)
- -(requires concomitant Class I mutation)
t(15;17)… Treatment (see Pharm form more on treating APL)
- -PML-RARA itself can be blocked with an RA analogue (ALL TRANS RETINOIC ACID, or ATRA)
- -ATRA induces differentiation of the blasts to granulocytes CLINICAL REMISSION
- **OTHER TRANSLOCATIONS TO RARA FROM OTHER LOCATIONS THAT PRODUCE APL MAY NOT RESPOND TO ATRA!!!!
t(15;17)…Clinical Presentation
- -DIC
- -Severe thrombocytopenia
t(15;17)…Morphology
- -Big blasts
- -Cleaved, “bat wing” nuclei
- -Many cytoplasmic granules
- -Aurer rods in stacks
t(15;17)…Immunophenotype
Weak/absent CD34
HLA-DR
CD13+
CD33+
t(15;17)…Prognosis
Good if diagnosis is made
CBFB-MYH11
inv(16)
OR
t(16:16)
CBFB-MYH11
- -Fusion protein of transcription factors w/ MYH1
- -5-8% of AML cases
- -Class II Mutant (dominant negative repressor of myeloid maturation)
- -Probably requires concurrent Class I mutation
CBFB-MYH11…Clinical presentation
younger pts/ kids
CBFB-MYH11…Morphology
- -Mixed granulocyte-monocyte features (“Myelomonocytic”)
- -Increased eosinophils in blood and marrow
CBFB-MYH11…Immunophenotype
CD34+ CD117+ (blasts) CD13+ CD33+ (granulocytes) CD14+ CD11b+ (monocytes)
CBFB-MYH11…Prognosis
Variably poor; optimal w/ high dose cytarabine
(SEE PHARM NOTES)
inv(16) prognosis good
AML w/ normal cytogenetics
40-50% of AML cases
AML w/ normal cytogenetics…Clinical Presentation
any age group
AML w/ normal cytogenetics…Morphology
undifferentiated OR
variably granulocytic OR
monocytic/monoblastic