Hema (AML M0-M7) Flashcards
Undifferentiated blasts in BM and PBS, AML—not otherwise categorized
AML Undifferentiated/Minimally Differentiated (M0)
30% blast cells – indistinguishable
AML Undifferentiated/Minimally Differentiated (M0)
% blast cells in M0
as indistinguishable
30%
M0 constitutes ___ of AML
5%
Age group for M0
Adults
blasts show no myeloid differentiation
medium-sized, have an agranular basophilic cytoplasm, round or slightly indented nuclei with 1 or 2 nucleoli, and dispersed chromatin
AML Undifferentiated/Minimally Differentiated (M0)
<3% of blasts react to Sudan black, a-naphthyl acetate, or stains that
detects myeloperoxidase
AML Undifferentiated/Minimally Differentiated (M0)
M1 constitutes ___% of AML
10%
Age group for M1
Adults
Azurophilic granules and Auer rods in the cytoplasm of the blast may suggest their myeloid nature
AML Differentiated without maturation (M1)
In other cases, the blasts resemble lymphoblasts, from which they are differentiated by positivity to myeloperoxidase stains or Sudan black in at least 3% of blast cells
AML Differentiated without maturation (M1)
M2 constitutes ___% of AML
30-45%
Age group for M2
ALL ages
Blasts may show azurophilic granules and Auer rods, and evidence of maturation is present
AML with maturation (M2)
> 10% of marrow cells being promyelocytes, myelocytes, and mature neutrophils
AML with maturation (M2)
In M2, >10% of marrow cells are
promyelocytes,
myelocytes,
mature neutrophils
In M2, <20% of marrow cells are
monocytes
< 20% being monocytes
AML with maturation (M2)
Neutrophils may show abnormally increased or decreased segmentation and lobulation
Basophils, eosinophils, and mast cells may be increased
AML with maturation (M2)
Highest number of Auer rods, collectively named as Faggot cells/Firewood cells (bundles)
AML Promyelomonocytic (M3)
30% blasts, >10% granulocytic lineage and >10% Promyelocytes
AML Promyelomonocytic (M3)
% blasts in M3
30%
> 10% in M3 are
granulocytic lineage
promyelocytes
Associated with chromosomal translocation of 15:17 (WHO)
AML Promyelomonocytic (M3)
Increased incidence of Disseminated Intravascular Coagulation (DIC)
AML Promyelomonocytic (M3)
aka Acute myelomonocytic leukemia/
Naegeli Biphasic M1 & M5
M4 constitutes ___% of AML
15-25%
Age group for M4
Elderly
Sometimes in patients preceding chronic myelomonocytic leukemia (CMML)
Acute myelomonocytic leukemia/ Naegeli Biphasic M1 & M5 (M4)
Indicator are monoblasts and promonocytes
Acute myelomonocytic leukemia/ Naegeli Biphasic M1 & M5 (M4)
In M4, these are large cells with round containing >1 prominent nuclei and abundant basophilic
cytoplasm, sometimes with fine azurophilic granules, vacuoles, and pseudopods formation
Monoblasts
In M4, these are less basophilic and more granulated cytoplasm, containing occasional
vacuoles, and azurophilic granules
Promonocytes
Irregular and indented nucleus
Acute myelomonocytic leukemia/ Naegeli Biphasic M1 & M5 (M4)
M5 constitutes ___% of AML
5% each type
M5 more common in children (<17 y/o)
M5a
M5 more common in adults (>18 y/o)
M5b
at least 80% of the leukemic cells are in the monocytic line
Acute monoblastic and acute monocytic leukemia (M5a, M5b)
at least 80% of the monocytic cells are monoblasts
acute monoblastic leukemia (M5a)
most of them are promonocytes
acute monocytic leukemia (M5b)
Acute erythroid leukemia subtypes
Erythroleukemia (erythroid/myeloid) – M6a
Pure erythroid leukemia – M6b
M6a constitutes ___% of AML
5%
In M6a, 50% of the nucleated cells in the bone marrow is
ERYTHROID
In M6a, these are dysplastic, containing multiple and megaloblastoid nuclei, the cytoplasm often
possessing poorly delineated, coalescing vacuoles
erythroid (50%)
In M6a, 20% of nonerythroid cells are
myeloblast
In M6a, these are similar to those in AML with
and without maturation
myeloblast
Very rare type of M6
M6b
In M6b, >80% of the marrow cells are
erythroid
Erythroblast in this type have deeply basophilic, often agranular, cytoplasm that may contain poorly
delineated vacuoles
Round nuclei have fine chromatin and >1 nuclei
Pure erythroid leukemia – M6b
M7 constitutes ___% of AML
5%
Age group for M7
ALL ages
In M7, 50% of the blast are from
megakaryocyte lineage
Often pleomorphic and have a basophilic, often agranular cytoplasm, cytoplasm may demonstrate pseudopod and bleb formation, indicating budding platelets in M7; Nuclei have fine chromatin and 1-3 nucleoli
Megakaryoblasts
In M7, these may be visible in the blood, as may be circulating micromegakaryocytes and megakaryocyte fragments
Dysplastic platelets
aka Schilling type
M5
aka Erythemic myelosis or Di Guglielmo syndrome
M6
aka MDS with excess blasts
M6
