Introduction, Classification, Clinical features, Lab Diagnosis

1. Acute Myeloid Leukemia
Dr Abdul Hafeez Kandhro
Senior Lecturer
B.Sc, M.Sc; Medical Technology,
M.Phil Biochemistry
Ph.D. Medical Technology
(Mahidol University, Bangkok , Thailand)

2. Acute Myeloid Leukemia
• Malignant neoplastic proliferation and accumulation of
immature and nonfunctional myeloid line of blood cells in
the bone marrow .
• Also known as acute myelogenous leukemia or acute
nonlymphocytic leukemia (ANLL)
• Most common Acute Leukemia affecting adults.
• As an Acute Leukemia, AML progresses rapidly and is
typically fatal within weeks or months if left untreated .

4. • In normal hematopoiesis, the myeloblast is an
immature precursor of myeloid white blood cells; a
normal myeloblast will gradually mature into a mature
white blood cell .
• However, In AML, a single myeloblast genetic changes
which "freeze“ the cell in its immature state and
prevent differentiation.
• When such a "differentiation arrest" is combined with
other mutations which disrupt genes controlling
proliferation, the result is an uncontrolled growth of
an immature clone of cells, leading to the clinical
entity of AML .
Acute Myeloid Leukemia- Pathophysiology

5. • The clinical signs and symptoms of AML result
from the growth of leukemic clone cells, which
tends to displace or interfere with the
development of normal blood cells in the bone
marrow .
• This leads to neutropenia, anemia, and
thrombocytopenia.
• The symptoms of AML are often due to the low
numbers of these normal blood elements.
Acute Myeloid Leukemia- Pathophysiology

6. Acute Leukemia
TRKC (15q25) TEL/TRKC t(12;15)(p13;q25)
GFR3 (4p16) TEL/FGFR3 t(4;12)(p16;p13)
FRK(6q21) TEL/FRK t(6;12)(q21;p13)
PCM1/JAK2 t(8;9)(p21-22;p23-24
FLT3 (13q12) ITD (80%), activation loop
kinase domain (15%)
KIT (4q12) JM region, activation loop kinase
domain
FLT3 (13q12)
Overexpression

7. AML t(8;21) mutation

8. Lab Diagnosis for fusion genes in AML

9. TrkC / Neurotrophic Receptor Tyrosine Kinase 3 NTRTK mutation

10. • Symptoms reflects B.M. failure to produce normally functioning
blood cells:
• Features of anemia: Weakness, shortness of breath and pallor
• Features of leukopenia: infections (septicemia, pneumonitis)
• Features of thrombocytopenia: Bleeding and increased
hemorrhagic tendency .
• Symptoms reflects B.M. hyperplasia and excessive accumulation,
infiltration and proliferation of malignant cells:
• Bone and Joint pain
• Hepatosplenomegaly
• Lymphadenopathy
• Gingival hypertrophy (hyperplasia) and oral lesions
Acute Myeloid Leukemia- Signs & Symptoms

11. Chloromas

13. • 1- Peripheral Blood:
• The leukocyte count ranges from < 1X109 to
>100X109 .
• Presence of blast on the blood smear.
• Neoplastic blast have few granules in the RNA
rich cytoplasm. According to the FAB:
1- Type I: typical blast features without granules.
2- Type II: has < 20 granules.
3- Type III: has numerous granules.
AML- Lab Diagnosis

14. • CBC and blood film examination :
• RBCs decreased, Hb less than 10g/dl
• Normocytic normochromic anemia (mild to severe), OR
• Slightly Macrocytic because of the inability to compete the
neoplastic cell for folate and vit-B12 or early release of Retic
cells
• Platelets count: reduced to normal
• WBC’s count: decreased mature leukocytes
• The appearance of malignant cells
• 2- Bone marrow:
• B.M. hyperactivation and hyperplasia
• Blasts : represents greater than 20 - 30% depends on the type of
Classification and type of Leukemia .
AML- Lab Diagnosis

15. AML- Lab Diagnosis

16. • Immunological markers (Surface, Cytoplasmic & Nuclear )
• TdT: Terminal Deoxynucleotidyl Transferase , differentiate
Myeloblasts from lymphoblasts (B & T precursors)
• CD markers : e.g. AML: CD11/CD13/CD33/CD117
• ALL (B-Cells): CD10/CD19/CD20/CD22
• ALL (T-Cells): CD2/CD3/CD5/CD7
• Cytogenetics: specific Chromosomal abnormalities
• Philadelphia chromosome (t(9;22)): common in CML
• t(8;21): AML-M2
• t(1;19), t(8;22), t(11,14) ALL
AML- Lab Diagnosis

17. • Classification, Based on:
1- FAB Group Classification:
• The Morphological criteria of PB and BM .
• The Immunophenotyping of Leukemic cells .
• The cytochemistry of Leukemic Cells .
• For Diagnosis, Blast count in PB or BM is >30% .
2- WHO Classification:
• Molecular/Genetic Features of Malignancies .
• FAB Class. Incorporated into WHO Class.
• For Diagnosis, Blast count in PB or BM is >20% .
AML- Lab Diagnosis for Classification

18. • AML-M0 (Acute Myeloblastic Leukemia without
differentiation):
• AML with no evident morphological differentiation
(no characteristic myeloid features)
• Bone marrow contains 30 to 90% blast forms with
clear cytoplasm (granules free )
• The blasts seen in AML and ALL are very similar;
with a high nuclear cytoplasmic ratio, immature
chromatin, nucleoli, and a variable amount of
cytoplasm .
• <3% of blasts are MPO and SBB positive
• Blasts are positive for CD13 and CD33 markers
FAB Classification

20. • AML-M1 (Acute Myeloblastic Leukemia, without
maturation):
• Poorly differentiated myeloblasts (more than
90% of NEB)
• Blasts are Type I (Agranular) and Type II (
Granular)
• MPO & SBB are positive (>3 but < 50%)
• CAE is with at least 10-20% positivity
• Blasts Express CD13/CD33/CD117
• Auer rods (may present but rarely seen)
FAB Classification

22. • AML-M2 (Acute Myeloblastic Leukemia, with
granulocytic maturation) :
• Evidence of maturation up to the Promyelocyte
stage (represents more than 10% of blasts)
• >50% of leukemic cells are MPO and SBB positive.
• 10-20% positivity for CAE
• Blasts Express CD13/CD33/CD117 , Also CD19/CD34
• Specific Translocation (t(8;21)), (less specific t(6;9))
• Auer rods are occasionally seen
FAB Classification

24. • AML-M3 (Acute Promyelocytic leukemia )
• Promyelocytes with heavy granulation (>30% of
NEC)
• Auer rods frequently seen (Faggot cells: cells with
bundles of AR)
• Cells are strongly positive with MPO and SBB
• Negative with CAE
• t(15;17) is a unique and common feature of AML-
M3.
• AML-M3 variant: showing the characteristic
bilobed hypogranular Promyelocytes
• AML-M3 and DIC ( Thromboplastic Substances )
FAB Classification

27. • AML-M4 (Acute Myelomonocytic leukemia):
• Cells are with granulocytic and monocytic
differentiation
• 20-80% of cells are positive for MPO, SBB and NSE.
• Differential diagnosis: serum lysozyme level >3 times
• 6q deletion or inversion are common.
• AML-M4 with Eosinophilia
• Eosinophils represents >5% of nonerythroid cells
• immature eosinophils positive for SE and PAS
FAB Classification

29. • AML-M5 (Acute Monoblastic leukemia):
• >80% of NEC are monocytic lineage
• >80% of cells are positive for NSE
• Cells are negative for MPO and SBB (weakly
positive in monoblast).
• del (11q), t(9;11), t(11;19)
• Two subclasses: Poorly (M5a) & well (M5b)
differentiated
• M5a: Predominance of monoblasts
• M5b: Predominance of promonocytes and
monocytes
FAB Classification

31. • AML-M6 (Acute Eythroblastic leukemia):
• Hypercellularity of B.M. with marked erythroid
hyperplasia
• >50% of ANC are of erythroid lineage .
• Blasts commonly show megaloblastoid characterestic
features including multi-nucleation, cytoplasm
vaculation
• Most erythroid precursors are positive for PAS (Fine
staining)
• Negative to weakly positive for MPO, SBB and SE
• AML (M6) against MDS :
• >50% or <50% Erythroblast of ANC:
• With >30% Blast of ANC ---> AML (M6)
• With <30% Blast of ANC ---> MDS
FAB Classification

33. • AML-M7 (Acute Megakaryoblastic leukemia):
• Uncommon form
• Extensive proliferation of Megakaryoblasts and
Megakaryocyte
• >50% of blasts are megakaryoblasts
• Blasts identified by platelets peroxidase
• Negative for MPO and SBB, while positive for
PAS
• Blasts Express CD41/CD42
• t(1;22) is common
FAB Classification

35. • 1- AML with recurrent Cytogenetic abnormalities
• usually translocation, in most cases the
chromosomal rearrangement create a fusion
gene, encoding a novel fusion protein
• I. AML with t(8;21)(q22;q22);(ETO/AML1):
• Present morphological as AML with maturation
• Core binding factor (CBF) also called AML1 is a
transcription factor critical for hematopoietic
development
• It is believed that HSC is the origin of leukemia
WHO Classification

36. • The t(8;21) translocation result in a chimeric
protein containing the N- terminal portion of
CBF (chromosome 21) and most of the ETO
protein from chromosome 8 ( nuclear protein
involved in the regulation of transcription)
• The fusion protein blocks the normal function of
CBF, and induce abnormal gene activation and
gene repression, this will lead to increase
proliferation with blocked differentiation
WHO Classification

37. • II. AML with abnormal B.M eosinphils
• inv (16)(p13;q22) or t(16;16)(p13;q22)(CBFB/MYH11):
• Present morphology as AML with monocytic and
granulocytic maturation and presence of abnormal
eosinphils in B.M
• Combination of acute myelomonocytic leukemia (AMML)
with abnormal eosinphilis is morphologically AMML Eo.
• Abnormal immature ( basophilic ) granules in the
eosinphils, promyelocyte, and myelocyte stages.
• The inv(16)(p13;q22) and t(16;16)(p13;q22) both result in
the fusion of the CBFB gene (16q22) to the smooth
muscle mysoin heavy chain gene SMMHC (MYH11) at
(16p13)
• The CBFB/SMMHC fusion protein binds to AML1/CBFa
and represses it is function as transcription factor.
WHO Classification

38. • III . AML with t(15;17)(q22;q12)(PML/RARa) and
variants:
• it is acute promyelocytic leukemia(APL), an AML in
which abnormal promyelocyte predominate.
• Both hypergranular ( typical APL) and hypogranular
or microgranular are seen.
• The presenting signs are DIC and bleeding .
• The typical t(15;17) gene rearrangement result in
the fusion of (PML/RARa) gene and reciprocal (
RARa/PML) gene
• (PML/RARa) mRNA has been identified in all APL
patient while (RARa/PML) mRNA in two third
WHO Classification

39. • The RARa protein is a nuclear hormone receptor
that bind to specific DNA sequence and controls
transcription.
• PML is growth suppressor nuclear protein
normally found in complex macromolecular
structure.
• The PML/RARa fusion protein leads to
formation of co-repressor complex molecules
that enhance the oncogenesis of APL
• It is believed that HSC is the origin of leukemia
WHO Classification

40. • IV. AML with 11q23(MLL) abnormalities:
• These leukemia associated with monocytic features
( monoblasts and promonocyte).
• Monoblast and promonocyte can have scattered
azurophilic granules and vacuoles.
• The MLL gene (11q13) is involved in a number of
leukemia associated translocation with different
partner chromosome.
• The MLL protein is a DNA binding protein that
interact with other nuclear protein and permits the
association of transcription factor which regulate
transcription.
WHO Classification

41. • 2- AML with multilinage Dysplasia ( with or without
prior MDS)
• It is an Acute leukemia ( >20% blast) with dysplasia
in more than 50% of the cells in two or more
myeloid cell lines
• It is occurs with or following MDS / MPD
• examples of dysplasia include: hypogranular PMNs,
psuedopelger-Huet anomaly, megaloblastic
erythrocyte, ringed sideroblast
• The cytogenetics abnormalities are variable and are
similar to these in MDS.
• HSC is the origin of leukemia
• poor prognosis
WHO Classification

42. • 3- AML and Myelodysplastic syndrome, therapy
related:
• These disorder arise as a result of cytotoxic
chemotherapy and / or radiation therapy
• Two major subtypes:
• I. Alkylating agent/ radiation treatment: initially
it start with MDS and eventually evolving AML.
• II. Topoisomerase II inhibitor treatment
WHO Classification

43. • 4- Acute Myeloid leukemias not otherwise categorized:
• Include all AML cases that not fulfill criteria for any of
other described
• The subtypes of this AML are classified according to
differentiated on morphology and cytochemical features
• I. AML Minimally Differentiated
• II. AML without Maturation
• III. AML with Maturation
• IV. Acute Myelomonocytic leukemia (AMML)
• V. Acute monoblastic leukemia and Acute monocytic
leukemia
• VI. Acute Erythroid leukemia (AEL)
• VII. Acute Megakaryoblastic leukemia
WHO Classification

44. • VIII. Acute Basophilic leukemia
• The most characteristic feature by
cytochemistry is metachromatic positivity with
toluindine blue
• IX. Acute panmyelosis with mylofibrosis
• it is occur with or following chemo and radio
therapy
• X. Myeloid Sarcoma
• a tumor of myeloblast or immature myeloid
cells occurs in the extramedullary site or in the
bone
WHO Classification

45. • No matter how badly someone
treat you;;;
• Never drop down to their level.
• Remain Calm
• Stay Strong, and
• Walk Away