Acute myeloblastic leukemia
(AML) without maturation***

M0

2

No azurophil granules

-

-

-

MY7(CD13)
MY9 (CD33)

-

Acute myeloblastic leukemia
(AML)

M1

19

A few azurophilic granules
or Auer rods

+/-

+/-

-

MY7 (CD13)
MY9 (CD33)
HLA-DR

del(5)
del(7)
+8

AML, with differentiation

M2

24

Some maturation beyond
promyelocytes; Auer rods

++

++

-

MY7
MY9
HLA-DR
MY10(CD34)

t(8;21)
t(6;9)

Acute promyelocytic leukemia
(APL)

M3

10

Hypergranular promyelocytes;
Auer rods

+++

+++

-

MY7
MY9

t(15;17)

Acute myelomonocytic
leukemia (AMML)

M4

30

>=20% monocytes;
monocytoid cells in blood

++

++

++

MY4(CD14)
MY7
MY9
MO1(CD11b)

inv(16)
del(16)
t(16;16)
t(4;11)

Acute monocytic leukemia
(AMOL)

M5

10

Monoblastic (M5A)
Promonocytic (M5B)

-/+

-

+++

MO1
MY4
HLA-DR

t(9;11)
t(10:11)

Acute erythroleukemia

M6

4

Predominance of erythroblasts;
dyserythropoiesis

-

-

-

Glycophorin A
MY9

-

Acute megakaryocytic
leukemia

M7

1

"Dry" aspirate; biopsy
with blasts and dysplastic

-

-

-

gpIIb/IIIa (CD41a)
HLA-DR±
MY9
MY10(CD34)

-

Age

< 45 years

< 2 years, > 60 years

Leukemia

De novo

Preceding myelodysplasia

Leukocytosis

< 25,000/mm³

> 100,000/mm³

Complete remission

Long duration

Short duration

Central nervous system
disease

Absent

Present

Cytoreduction

Rapid

Delayed

Auer rods

Present

Absent

Eosinophils

Present

Absent

Dysplastic morphology

Absent

Present

FAB type

M2, M3, M4

M0, M1, M5, M6, M7

Myeloid

-

CD34+

HLA-DR

Negative

Positive

TdT

Absent

Present (weak correlation)

Lymphoid

CD2+ or CD19+

Biphenotypic

Peroxidase

High score (FABM1)

Low score (FAB M1)

Cytogenetics
(often an independent
prognostic factor)

t(15;17),t(8;21),
inv(16)/del(16q)
normal karyotype

-7,del(7q);-5;3q or 11q23
abnormalities, t(9;22),
+8,20q-, complex karyotypes