Leukemia

Leukemia

1. The leukemias

2. Leukaemias
Definition
•Leukaemia is a malignant disease of the
haemopoietic tissue,characterized by the
replacement of normal bone marrow elements
with abnormal blood cells.
•Leukaemic cells are frequently present in the
peripheral blood, commonly invade spleen, liver
and lymph nodes and other tissues of the body,
eg testes, brain, meninges and skin

3. Classification of Leukaemias
Acute leukaemia
•Acute lymphoblastic leukaemia
•Acute myeloid leukaemia
Chronic leukaemia
•Chronic myeloid leukaemia
•Chronic lymphocytic leukaemia

4. Classification of leukaemias
•Other chronic lymphoid leukaemias
Hairy cell leukaemias
Prolymphocytic leukaemia
Lymphoma/leukaemia
•‘Pre - leukaemia’ - myelodysplastic
syndrome

5. Pathogenesis of Acute leukaemia
•Origin of leukaemia at the genetic level appears
to be related to mutations and altered
expression of oncogenes and tumor suppressor
genes
•Oncogenes regulate cell proliferation and
differentiation
•Abnormal oncogene or tumour suppressor gene
expression induced by translocation and genetic
fusion or mutation results in unregulated cellular
proliferation

6. Pathogenesis of Acute leukaemia
•Genetic alteration occurs within a single
abnormal stem cell or progenitor cell in the
marrow.
•Successive generation of cells derived by
mitosis from the original abnormal cell
gives rise to a clonal population, which,
when sufficiently large, causes clinically
apparent disease

7. Pathogenesis of Acute leukaemia
•Acute leukaemia, blasts cells fail to differentiate
normally, further divisions continue, results in
accumulation, replacement of normal cells by
lymphoblasts or myeloblasts – bone marrow
failure
•Clinical condition correlate with total number of
leukaemic cells in the body.
•When 60% or more of total marrow cells –
peripheral blood involvement, liver, spleen and
lymph nodes are infiltrated.

8. Epidemiologic aspects of
leukaemia
•Host factors
1. Heredity
•Appears not to be inherited but increased
predisposition in some individuals.
Family members of leukaemia pts – possible
shared environment
Identical twin –shared placental circulation
(possible in utero exposures)

9. Epidemiologic aspects of
leukaemia
2. Congenital chromosomal abnormalities
Disorders with genetic abnormalities predispose
to acute leukemias :
- Down’s syndrome 10 to 20 fold increase of
acute leukaemia. AML 1 gene identified in
chromosome 21
-Fanconi’s anaemia (AML)
-Ataxia telaniectasia (ALL,NHL)

10. Epidemiologic aspects of
leukaemia
3. Immunodeficiency
•Hereditary immunodeficiency states,
high incidence of lymphoproliferative disorder
4. Chronic marrow dysfunction
MDS, myeloproliferative disorders, aplastic
anaemia,
increased risk of acute leukaemia
transformation

11. Epidemiologic aspects of
leukaemia
•Environmental factors
1.Ionizing radiation
Exposure associated with develoment of acute and chronic leukaemia
Illustrated in populations exposed to nuclear weapons in Hiroshima and
Nagasaki
2. Chemicals and drugs
Benzene – most frequently documented chemical toxin
Alkylating drugs – pts on combined chemoradiotherapy for Hodgkin’s
disease
Chemotherapy – 10 % - 20% of all AML, secondary AML

12. Epidemiologic aspects of
leukaemia
3. Viruses
Human T cell leukaemia/lymphoma virus
Implicated causative agent for adult T cell
leukaemia/lymphoma
Epstein Barr virus linked to African Burkitt
lymphoma – high grade B cell lymphoma

13. Incidence
•Acute leukaemia comprises > 50% of
leukaemia seen in clinical practice
•ALL, common form in children, peak 3-4
yrs falling off by 10 yrs
•AML occurs in all age groups
common type in adults, elderly, only 10
-15% of leukaemia in childhood

14. Incidence
•Chronic leukaemias
•Generally disease of adults
•CLL extremely rare in children, unusual
before 40 yrs
•CML seen at any age, peak incidence 30-
50 yrs, rare in children
•Distinct juvenile variant (jCML) in children

15. Comparison of Acute and Chronic
leukaemia
Acute Chronic
•Age All ages Adults

•Clinical onset sudden insidious
•Course <6 months 2-6 yr
•Leukaemic cells immature mature
•Anaemia mild-severe mild
•Thrombocytopenia mild-severe mild
•TWBC variable increase
•Organomegaly mild prominent

16. Acute leukaemia
•Acute leukaemia is defined as the
presence of >30% blasts in the bone
marrow at clinical presentation.
•Subdivided into two types on the basis of
blasts.
•Acute lymphoblastic leukaemia
•Acute myeloid leukaemia

17. Clinical features of acute leukaemia
Pathogenesis Clinical features
•Bone marrow failure
•Anaemia Fatigue, malaise,pallor
•Thrombocytopenia Bruising, bleeding
•Neutropenia Fever, infection

18. Clinical features of acute leukaemia
Organ infiltration
•Marrow expansion Bone or joint pain
•Spleen Splenomegaly
•Liver Hepatomegaly
•Lymph nodes Lymphadenopathy
•CNS CNS symptoms
•Gums, mouth gum hypertropy,
oral lesions

19. CLASSIFICATION
•Morphology
–French-American-British (FAB) classification
– WHO classification
•Immunophenotype- ALL
Importance of classification
–Determine mode of treatment
–Prognostic value

20. FRENCH-AMERICAN-BRITISH (FAB)
CLASSIFICATION
ACUTE LEUKEMIA
Acute myeloid leukemia Acute lymphoblastic leukemia
M0 undifferentiated
M1 without maturation
M2 with granulocytic maturation
M3 acute promyelocytic
M4 granulocytic and monocytic maturation
M5 monoblastic (M5a) or monocytic (M5b)
M6 erythroleukemia
M7 megakaryoblastic
L1
L2
L3 (Burkitt)

21. FAB classification
•Acute lymphoblastic leukaemia subdivided
•Based on morphology and cytochemistry
•L1
•L2
•L3

22. ALL- L1
•Blasts are small
•Homogenous
•High N/C ratio
•scanty cytoplasm

23. ALL- L2
•Blasts are larger
•heterogenous
•Low N/C ratio
•More abundant
cytoplasm

24. ALL- L3
•Blasts are deeply
basophilic
•Vacuolated cytoplasm

25. FAB classification
AML
•M0 – undifferentiated
•M1 – without maturation
•M2 – with granulocytic maturation
•M3 – acute promyelocytic leukaemia
•M4 – granulocytic and monocytic maturation
•M5 – monoblastic (M5a)
• monocytic (M5b)
•M6 – erythroleukaemia
•M7 - megakaryoblastic

26. Myeloblast with auer rod

27. FAB classification
•AML M0

28. AML-M1
•Blast cells have few
azurophilic granules
•May have auer rods

29. AML –M2
•Multiple granules
•May have Auer rods
•With granulocytic
differentiation

30. AML- M3
•Abnormal
promyelocytes
•Prominent granules
•Multiple Auer rods

31. AML- M4
•Have monocytoid
differentiation
•> 20% or more is
monocytoid cells

32. AML- M5a
•Monoblastic
•> 80% of blasts are
monoblasts

33. AML- M5b
•Monocytic
•< 80% of blasts are
monoblasts

34. AML- M6
•Predominance of
erythroblast
•Dyserythropoiesis

35. AML- M7
•Megakaryoblast with
cytoplasmic blebs

36. FAB M3 and M 4 /M 5 features
FAB M3
•Bleeding tendency
•DIVC
•Pancytopenia
•FAB M 4 / M 5
•Gum hypertrophy and infitration
• Skin involvement
•CNS disease
•Granulocytic sarcoma – isolated mass of leukaemia
blasts

37. Laboratory and Radiographic Work-up:
• CBC with manual differential
• Uric Acid level
• Clotting studies (PT, PTT, D-dimer, fibrinogen)
• Bone marrow aspirate and biopsy
• Chest xray
• Echocardiogram

38. Diagnosis Of Acute Leukemia
•Demonstrate > 30% blasts in the bone
marrow.
•Diagnosis of acute leukemia is based on
the following:
1.Morphology of the blasts
2.Cytochemistry( MPO,Sudan black- B,NSS,
PAS).
3.Immunophenotyping
4.Cytogenetics
5.Molecular

39. LABORATORY DIAGNOSIS
•Complete blood count
–Normochromic normocytic
anemia
–Thrombocytopenia
–WBC- variable
•Peripheral blood film
–Blasts
•Bone marrow examination
–Hypercellular
–> 30% leukemic blasts
•Cytochemistry
–Myeloperoxidase
–Sudan black
–Non-specific esterase
–Periodic acid-Schiff
–Acid phosphatase
•Flow cytometry
–Myeloid and/or lymphoid
markers
•Genetic analysis

40. •Others
–Lumbar puncture- leukemic cells
–Uric acid, LDH, Calcium – may be raised
–Renal & liver function test- baseline
–X-ray- lytic bone lesion, enlarge mediastinum
(T-ALL)

41. Morphology
•Majority of leukemias at most of the
centers world over are diagnosed by
morphology and cytochemistry
•Blasts cells are large cells with:
a)High N:C ratio
b)Nucleus is large with open chromatin
c)Nucleoli 1- 5
d)Thin rim to moderate amount of cytoplsm

42. Cytochemistry
•Bone marrow smears are stained to
determine specific enzymes or other
proteins produced by cellular organelles.

43. Cytochemistry
ALL AML
Myeloperoxidase _ +, auer rods

Sudan black _ +, auer rods
Periodic acid schiff + + M6
(coarse granular) (fine blocks)

Nonspecific esterase _ + M4,M5
Acid phosphatase + T ALL +M6
(golgi staining) (diffuse)

44. Periodic acid- Schiff
Coarse block positivity- ALL Fine blocks – M6

45. Sudan black
•Black staining in
cytoplasm

46. Non-specific esterase
•Positive in M4, M5
•Monoblast cytoplasm
–Orange staining
•Myeloblast cytoplasm
–Blue staining

47. Immunological classification
AML ALL
Marker precursor B T
Myeloid
CD 13 + - -
CD 33 + - -
Glycophorin + M 6 - -
Platelet antigen CD41 +M 7 - -
Myeloperoxidase +M 0 - -

48. Immunological classification
AML ALL
Marker precursor B T

B lineage ALL
CD 19 - + -

cCD22 - +or- -

CD 10 - + -
cIg - +pre B -

49. Immunological classification
AML ALL
Marker precursor B T
T lineage
CD 7 - - +

cCD3 - - +
TdT - + +

50. Cytogenetics
•Essential component in newly diagnosed leukaemic
pts
•Major role in diagnosis
•Subclassification
•Selection of appropriate therapy
•Monitering effects of therapy

51. Cytogenetics
Chromosomal abnormalities associated with distinct
types of leukaemia
•t (15;17) unique to APML (FAB M3)
•Inv (16) AMML with abnormal eosinophilia (M4Eo)
•t (9;22) Ph chromosome in CML , ALL

52. AML- M2 AML- M4

53. AML-M3
•blocks differentiation at
the promyelocyte
stage
•All-trans retinoic acid
(ATRA) allow them to
differentiate and to
apoptose

54. ALL

55. Prognostic value
good poor
AML t (15;17) – M3
t (8;21) – M2
Inv (16) –M4
Del of chr 5 or 7
t (6;9)
11q23
ALL Ph+
11q23

56. Molecular genetics
•Primarily used for confirmation of suspected
chromosomal abnormality not detected by
conventional cytogenetics.
•Monitoring minimal residual disease following
therapy
Hand out – molecular correlation of common chromosomal abnormalities in acute
leukaemia

57. Prognosis in ALL
Good Poor

•WBC Low High > 50,000

•Sex Girls Boys
•Immunophenotype c-ALL B ALL
•Age Child Infants<2 yrs,
adults
•Cytogenetics Normal Ph+, 11q23
or hyperdiploidy

58. Prognosis in ALL
Good Bad

•Time to clear blasts <1 week >1 week
from blood
•Time to remission <4 weeks >4 weeks
• CNS disease at presentation Absent Present
•Minimal residual disease negative at still positive
1-3 months 3-6 months

59. Prognosis in AML
Good Bad
•Cytogenetics t(15:17) delection of chromosome
t(8;21) 5or7
inv (16) 11q23
t(6;9)
•Bone marrow response <5% blasts >20% blasts after
to remission induction after first course first course
•Age < 60 yrs >60 yrs

60. CHRONIC MYELOID LEUKAEMIA

61. Chronic Myeloid Leukaemia
•Disorder proliferation of haemopoietic stem cells
•Incidence increases with age
–Median age: 40 - 60
–Youngest so far – 12 years old
•Slightly higher incidence in males
–Male-to-female ratio—1.3:1
•Cause
–Unknown
–Slightly increased risk following high dose irradiation: Japanese
atomic bomb survivor
•Median survival: 5 years

62. Melo. Blood. 1996;88:2375.
Pasternak et al. J Cancer Res Clin Oncol. 1998;124:643.
The Ph Chromosome and the bcr-abl Gene: The t(9;22)
Translocation
FUSION PROTEIN WITH CONSTITUTIVE
TYROSINE KINASE ACTIVITY
bcr-abl
bcr
Philadelphia Chromosome
(or 22q-)
Chromosome 9 q+
abl
Chromosome 9
Chromosome 22

63. Pathogenesis
•Translocation of genetic material between chromosom 9 and 22
results in fusion gene: bcr – abl (Philadelphia chromososom)
• BCR-ABL fusion gene (M-BCR) encodes a protein of molecular
weight 210 kDa that has greater tyrosine kinase activity than the
normal ABL gene product.

64. The Ph Chromosome and the bcr-abl Gene: bcr-abl Gene
Structure
p210Bcr-Abl
c-abl1
p185Bcr-Abl2-11
2-11
Chromosome 9
c-bcr
Chromosome 22
2-11
Exon on chromosome 22
Exon on chromosome 9
Introns
CML breakpoints
Melo. Blood. 1996;88:2375.
Pasternak et al. J Cancer Res Clin Oncol. 1998;124:643.

65. Prevalence of the Philadelphia Chromosome in
Leukemias
Faderl et al. Oncology (Huntingt). 1999;13:169.
%

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0
20
40
60
80
100
CML ALL (adult)ALL (pediatric)AML
95
30
5
2

66. Clinical Presentation
•Asymptomatic in ~50% of cases
–Incidental finding of leucocytosis
•Common symptoms
–Fatigue
–Weight loss/anorexia
–Abdominal fullness
•Common signs
–Palpable splenomegaly
•Common laboratory findings
–Abnormal differential WCC
–Leukocytosis
–Thrombocytosis
–Anemia
–Basophilia

67. CML
•3 clinical stages
–Chronic phase
–Accelerated phase
–Blastic phase
•40% patient: disease progress from chronic to blastic
phase
•Blast transformation occur: 3 – 5 years

68. Laboratory investigations in CML
• FBC/FBP – anaemia, leucocytosis, immature
granulocytes, basophilia, thrombocytosis, occasional blast
(chronic phase)
•NAP score – low
•LDH – high
•BMAT – Hypercellular marrow with granulocytic
hyperplasia. Blasts not more than 10%.
•Cytogenetic – Philadelphia chromosome
•Molecular analysis – FISH/RT-PCR

71. Hematologic Parameters by Phase of CML
Parameter Chronic Accelerated Blastic
WBC count (/L)High High High
Blasts (%) 1-10 ³10, < 20 ³30
Basophils (%) ­ ³20 Basophilia
Platelets ­ or normal ¯ or ­ ¯
Bone marrow Myeloid hyperplasia Blasts+++