acute lymphoblastic leukemia

1. DR ARUN HALDIA
DR HARENDRA YADAV

2. 1) INTRODUCTION
2) ETIOLOGY
3) PATHOGENESIS
4) CLINICAL PRESENTATION
5) INVESTIGATION
6) CLASSIFICATION
7) DIFFERENTIAL DIAGNOSIS
8) SUMMARY

3. INTRODUCTION
 Leukaemia are the neoplastic proliferation of
hemopoietic cells
 Divided into 2 broad categories depending
upon cell lineage-
ACUTE
MYELOID
LEUKAEMIA (AML)
ACUTE
LYMPHOBLASTIC
LEUKAEMIA (ALL)

4. Hematopoietic
stem cell
Neutrophils
Eosinophils
Basophils
Monocytes
Platelets
Red cells
Myeloid
progenitor
Lymphoid
progenitor
B-lymphocytes
T-lymphocytes
Plasma
cells
naïve
ALL
AML
4

6. AML: the myeloblast is a
large blast with a
moderate amount of
granular cytoplasm, fine
lacy chromatin &
prominent nucleoli. Auer
rods may be seen
ALL: the lymphoblast
is a small blast with
scant cytoplasm,
dense chromatin,
indistinct nucleoli,
and no Auer rods or
granules.

7.  ALL are neoplasm composed of immature B
(pre-B) or T (pre-T) cells
 ALL is primarily a disease of children,75% of
cases occur under 6 yr
 B Cell (75-80%) or T Cell(15-20%)
 B-ALL peak at 3yr while T-ALL peak at
adolescence
 Slight Male predominance is seen

8.  By convention, the minimum number of bone marrow
lymphoblasts required for diagnosis is set at 25%
 In children - ALL the most common malignant
disease

9. ETIOLOGY
 Higher socio-economic group
 Genetic abnormality
 Down syndrome
 Radiation exposure
 Smoking
 Industrial exposure to chemicals(benzene)

10. PATHOGENESIS
 App 90% of ALLs have numerical or structural
chromosomal changes
 MC is hyperploidy, but hypoploidy & variety of balanced
translocation also seen
 These chromosomal aberrations dysregulate the expression
& function of transcription factors that are required for
normal B & T cell development
 A higher fraction of B-ALL have loss of function mutation
in PAX5, E2A, EBF
 Up to 70% T-ALL have gain of function mutation in
NOTCH1
 These mutations disturb the differentiation of lymphoid
precursors & promote maturation arrest
 Single mutations are not sufficient to produce ALL

11. CLINICAL PRESENTATION

12. Clinical Presentation
 Abrupt onset
 Nonspecific Symptoms
 Fatigue
 pallor
 Easy bruising
 Bleeding
 fever
 Dyspnoea
 Dizziness
 weight loss
 Joint, extremity
pains
 CNS involvement
 Lymphadenopathy
 Splenomegaly
 Hepatomegaly
 Gonads
 Mediastinal mass

13. INVESTIGATION
1. Peripheral blood smear
2. Bone marrow examination
3. Cytochemistry
4. Immunohistochemistry
5. Other : testicular Bx, CSF examination, chest X-ray

14. PBS EXAMINATION
 Normocytic normochromic anaemia
 TLC : decrease, normal or may be increase
 Lymphoblasts
 Granulocytopenia
 Thrombocytopenia

15. ALL : PERIPHERAL BLOOD SMEAR

16. ALL : BM EXAMINATION
 Hypercellular d/t proliferation of leukaemic blasts
 B-ALL : The blast have varied appearance from a
homogenous population of small cells with a round to
slightly irregular nucleus, condensed chromatin &
inconspicuous nucleoli to large cells with irregular, clefted
or indented nuclei, variably distributed chromatin & one
or more distinct nucleoli.
 cytoplasm is scant to moderate & slight basophilic to
deeply basophilic as cell size increase
 T-ALL : Compared with B- lymphoblast, T-lymphoblast
show greater nuclear convulation & significant nuclear
hyperchromasia

17. ALL : BM EXAMINATION
 Mitotic figure : higher in T-ALL than B-ALL
 Myeloid precursors : decrease
 Megakaryocytes : decrease

18. ALL (BMA) : lymphoblast with condensed nuclear
chromatin ,small nucleoli & scant agranular cytoplasm

21. STAIN AML ALL
MPO + -
SBB + -
NSE + in M4, M5 -
PAS + (fine block in
M6) BLOCK +
ACID
PHOSPHATASE
+ in M6(diffuse) + T- ALL 21
CYTOCHEMISTRY

22. Myeloperoxidase
stain
Lymphoblast:
negative

23. Periodic acid-schiff stain : block positive
ALL

24. Acid phosphatase
focal perinuclear positivity
(T-ALL)

25. MARKER FOR THE Dx OF ALL
LINEAGE ANTIGEN
Precursor-B ALL CD19, CD10, CD79a, TdT, cCD22*,
HLA-DR, cCD79a*
Precursor-T ALL CD1, CD2, CD3, CD4, CD5, CD7
CD8, TdT, cCD3*

26. OTHER INVESTIGATIONS:
 CSF examination for lymphoblast
 Testicular biopsy-to rule out residual disease
 Chest X-ray

27. CLASSIFICATION
 FAB classification
 Immunologic classification
 WHO classification

28. FAB CLASSIFICATION
BASED ON MORPHOLOGY
Subtype Blasts Morphology Occ (%)
L1
Small round blasts, scant cytoplasm,round
nucleus, homogenous chromatin &
indistinct nucleolus
75%
L2
Pleomorphic larger blasts, moderate
amount of cytoplasm,irregular nuclei, fine
chromatin one or more often large distinct
nucleoli.
20%
L3
Large blasts, moderate amount of
basophilic vacuolated cytoplasm, round to
oval nucleus with stippled chromatin & one
or more, distinct nucleoli.
05%
28

31. Bone marrow aspirate smear showing ALL-L3 blast with large
nucleus, basophilic cytoplasm with prominent vacuolization
(Burkitt type)

32. CRITICISM OF FAB CLASSIFICATION
 It does not include
immunophenotyping
cytogenetics
molecular characteristics
• Immunological subtypes of ALL
• Biphenotypic leukemia
• Limited relevance to therapeutic or prognostic
implication

33. IMMUNOLOGIC CLASSIFICATION
1. B-ALL
2. T-ALL
3. MIXED-LINEAGE ACUTE LEUKEMIA
4. UNDIFFERENTIATED ACUTE LEUKEMIA

34. Immunologic classification of acute
lymphoblastic leukemias : B-ALL
B- lineage (80%) Markers
Pro-B (8-10%) HLADR(+), Tdt(+), CD10(-), CyIg(-), SmIg(-)
Common(50%) HLADR(+), Tdt(+), CD10(+), CyIg(-), SmIg(-)
Pre-B (20%) HLADR(+), Tdt(-), CD10(-), CyIg(+), SmIg(-)
Mature-B (1-2%) HLADR(-), Tdt(-), CD10(-), CyIg(-), SmIg(+)
34

35. Case of ALL:
Immunocytche
mistry on bone
marrow
aspirate smear
demonstrate
CD 10 positivity,
such cases have
favourable
prognosis

36. Immunologic classification of acute
lymphoblastic leukaemias
T-ALL
 Pas negative, acid phosphatase positive
 CD1+, CD2+, CD3+,CD4+,CD5+, CD7+, CD8+, TdT, cCD3

37. IMMUNOLOGIC CLASSIFICATION OF ALL :
MIXED LINEAGE ACUTE LEUKEMIA
BIPHENOTYPIC LEUKEMIA
 These comprise 1-2% of acute leukemia
 There are two population of cells
(A) large cells with differentiation as myeloblast
which are MPO+, SBB+, usually with Auer rods, or
monoblastic morphology
(B) smaller blasts with L1 morphology & may have
hand-mirror morphology. blast express a mixture of
myeloid & lymphoid antigens

38. IMMUNOLOGIC CLASSIFICATION :
UNDIFFERENTIATED ACUTE LEUKEMIA
 Blasts usually have L2 morphology but there is no
lineage differentiation with expression of HLA-DR,
CD34, CD38, CD7, and TdT

39. WHO Classification
 B-Lymphoblastic leukaemia, NOS
 B-Lymphoblastic leukaemia with recurrent genetic
abnormalities
 T-Lymphoblastic leukaemia

40. WHO Classification
B-Lymphoblastic
leukaemia, NOS
B-Lymphoblastic
leukaemia with
recurrent genetic
abnormalities
T-
Lymphoblastic
leukaemia
B-Lymphoblastic leukaemia with t(9:22) (q34;q11.2); BCR-ABL 1
B-Lymphoblastic leukaemia with t(v:11q23);MLL rearranged
B-Lymphoblastic leukaemia with t(12;21) (p13;q22); TEL-AML1 (ETV6-
RUNX 1)
B-Lymphoblastic leukaemia with hyperdiploidy
B-Lymphoblastic leukaemia with hypodiploidy
B-Lymphoblastic leukaemia with t(5:14) (q31;q32);IL3-IGH
B-Lymphoblastic leukaemia with t(1:19); E2A-PBX 1 (TCF3-PBX 1)

41. B-LYMPHOBLASTIC
LEUKAEMIA, NOS

42. B-Lymphoblastic leukaemia, NOS
CRITERIA ≥ 25% blast, involving BM / PB committed to B cell
lineage
AGE •Common in Children
•75% cases below 6Yrs of age
INCIDENCE 1-4.75 / 1 lakh per year
MORPHOLOGY •Bone marrow aspiration : Blast may be small or large
•Small- scant cytoplasm, condensed chromatin,
indistinct nucleoli
•Large- moderate blue-grey cytoplasm, occasionally
vacuolated, dispersed nuclear chromatin with multiple
nucleoli
•Nuclei- round, irregular or convoluted
•10% blast with primary azurophilic granules
•BONE MARROW BIOPSY : relatively uniform
appearance with round to oval, indented or convoluted
nuclei, finely dispersed chromatin & inconspicuous to
prominent nucleoli
42

43. Pre B-ALL, BM smear with several lymphoblast with high N:C and
Variably condensed nuclear chromatin

44. Pre B-ALL showing medium size blast with
numerous cytoplasmic coarse azurophilic granules

45. B-Lymphoblastic leukaemia, NOS
IMMUNOPHENOTYPE
•CD19, CD79a, cyCD22 +ve
•CD10, sCD22, CD24, PAX5, Tdt +ve in most cases
•CD20, CD34 variable expression
GENETICS •Nearly all cases with DJ rearrangement of IgH gene
•70% cases with TCR gene rearrangement
•Others- Del 6q, 9p & 12p
CYTOCHEMISTRY
•PAS +ve
•NSE +ve
•MPO –ve
•SBB –ve (granules if present may stain light grey but
less intense than myeloblast)
PROGNOSIS •Good in children
•Poor in adults
•Cure rate 80% in children
less than 50% in adults
45

46. Pre B-ALL,showing nuclear Tdt positivity
in a bone marrow biopsy
Pre B-ALL : TdT positivity in a bone marrow biopsy

47. B LYMPHOBLASTIC
LEUKAEMIA WITH
RECURRENT GENETIC
ABNORMALITIES

48. B-ALL with t(9:22)
(q34;q11.2); BCR-
ABL 1
B-ALL with
t(v:11q23);MLL
rearranged
B-ALL with t(12;21)
(p13;q22); TEL-AML1
(ETV6-RUNX 1)
•Neoplasm of
lymphoblast with
trans b/w BCR-
ABL gene
•Translocation b/w
MLL gene at 11q and
any part of a large
No. of different
fusion partner
•WBC count very
high >1 lac/micro L
•CNS involvement
•. Translocation b/w
ETV 6 and RUNX 1
gene
•25 % of all B-ALL
AGE Common in adults
than children.
Accounting 25%
of adult ALL & 2-
4% of childhood
ALL
It is the most
common type of
leukaemia in <1 year
of age
Common in
children
Not seen in infants
Rare in Adults
MORPHOLOGY No unique
morphology
No unique
morphology
No unique
morphology
48

49. B-ALL with t(9:22)
(q34;q11.2); BCR-
ABL 1
B-ALL with
t(v:11q23);MLL
rearranged
B-ALL with t(12;21)
(p13;q22); TEL-AML1
(ETV6-RUNX 1)
IMMUNO-
PHENOTYPE
•CD10+, CD19+,
Tdt+
•CD25+
•CD19+, CD10- & CD
24 –ve
•Pro B +ve for CD5
•Condroitin sulphate,
proteoglycan,
neuroglial Ag2
expressed
•CD19 +ve, CD10+ve
& CD34+ve
•CD13 Frequently
expressed
GENETICS •BCR gene fuse
with ABL 1 gene &
produce BCR-ABL
fusion protein
•190KD (children)
•210KD (adult)
•MLL gene have
many fusion partner
•m/c AF4 (4q21)
•Other ENL (19p13),
AF9 (9p22)
•ETV6-RUNX1
fusion protein
inhibit transcription
factor RUNX1
PROGNOSIS •Poor both in child
& adults
•Poor •Good
•>90% cure rate
49

50. Pre B-ALL with a t(9:22) abnormality BMA :
lymphoblast have moderate amount of cytoplasm
with numerous coarse azurophilic granules

51. Bone marrow biopsy : marrow is replaced by
lymphoblast, mitotic figure also seen in a case of
t(9:22) abnormality

52. B-ALL with
hyperdiploidy
B-ALL with
hypodiploidy
CRITERIA •Blast contains >50 & usually
<66 chromosomes
•No translocation
•No other structural
alteration
•Blast contain <46 or 45
chromosomes
AGE •Common in children
•Rare in adult
•Both in children & adults
•Haploid ALL (23-29 chrom)
seen in childhood
INCIDENCE •25% cases of B-ALL •5% if chromosomes<46
•1% if chromosomes<45
MORPHOLOGY •No unique morphological
feature
•No unique morphological
feature
52

53. B-ALL with
hyperdiploidy
B-ALL with
hypodiploidy
IMMUNO-
PHENOTYPE
CD19, CD10 +ve
CD34+ve
CD45-ve
•Blast have Pre-B phenotype
•CD19, CD10+ve
GENETICS
•Numerical ↑se in chromosome
•No structural abnormalities
•21,X,14,4 chrom extra copies
(m/c)
•1,2,3 chrom (least common)
•Trisomy 4,10,17
•Loss of one or more chromo
having from 45 chrom to near
haploid
•Detect by standard
karyotyping FISH &
flocytometry
PROGNOSIS • Favourable Px
•Cure rate >90% in children
•Over all Poor Px
•45-46 chrom then better Px53

54. B-ALL with
t(5:14)(q31:q32); IL3-IGH
B-ALL with
t(1:19);(q23:p13.3);E2A-
PBX1 (TCF3-PBX1)
•Blast having translocation b/w
IL3 gene & IGH gene
•Resulting in eosinophilia
Translocation in b/w E2A gene
& PBX1 gene
AGE •Both in children & adult •Common in children
•Also seen in adults
INCIDENCE •Rare disease
• <1% of all ALL
6% of all cases of B-ALL
MORPHOLOGY •Blast with typical morphology
•Increasing circulating
eosinophills
•No unique morphology
54

55. B-ALL with
t(5:14)(q31:q32); IL3-
IGH
B-ALL with
t(1:19);(q23:p13.3);E2A
-PBX1 (TCF3-PBX1)
IMMUNOPHE
NOTYPE
•CD19, CD10 +ve •CD19, CD10 +ve
•Cy μ heavy chain +ve
•CD9 strongly expressed in
absence of cy μ H chain
GENETICS •Functional rearrangement b/w
IL3 gene (5) & IGH gene (14)
•Resulting in over expression of
IL3 gene which results in
eosinophilia
•E2A-PBX1 translocation results
in a fusion protein that has an
oncogenic role
PROGNOSIS -------- •Poor
55

56. T-Lymphoblastic
leukaemia

57. T-Lymphoblastic leukaemia
CRITERIA •Neoplasm of lymphoblast committed to T cell lineage involving
BM & PB
• >25% BM blast
AGE & SEX •Common in adolescents than young children
•Male >female
INCIDENCE •15 % of childhood ALL
•25 % of adult ALL
C/F •High leukocyte count
•Thymic infiltration is very common & may be associated with
pleural effusion, pericardial effusion, & SVC obstruction
•mediastinal mass
•Lymphadenopathy, hepatosplenomegaly
57

58. T-Lymphoblastic leukaemia
MORPHOLOGY •Composed of small to medium sized blast.
•Nuclear shape- round to irregular
•Small blast with scant cytoplasm ,condensed chromatin
& no prominent nucleoli
•Large blast with finely dispersed chromatin & relatively
prominent nucleoli
•Mitosis : higher than B-ALL
CYTOCHEMISTRY •Acid phosphatase +ve (Focal), not specific
IMMUNOPHENOTYPE •Tdt +ve
•CD99, CD34, CD1a most specific
• CD1a, CD2, CD3, CD4, CD5, CD7, CD8 variable +ve
•CD7, Cyt CD3 most often +ve
58

59. Blood smear : The lymphoblast vary in size from
large cell to small cell with high N:C ratio &
condensed chromatin, no nucleoli

60. Pre T-ALL (BMA) : numerous blast with delicate
chromatin round to oval nuclei & distinct nucleoli

61. B M aspirate smear in Pre T-ALL showing numerous lymphoblast with
nuclear irregularities,dispersed chromatin,occasionally
Distinct nucleoli ,and small amount of agranular basophilic cytoplasm

62. Bone marrow biopsy : replacement of marrow by blast

63. BMB : lymphoblasts vary in size from large cell to small cell
with high N:C ratio & mitosis

64. T-Lymphoblastic leukaemia
IMMUNOPHENOTYPE
Intrathymic differentiation
•Pro T- cCD3 +ve, CD7 +ve, CD2-ve, CD1a-ve, CD34 ±
•Pre T- cCD3 +ve, CD7 +ve,CD2+ve, CD1a-ve, CD34 ±
•Cortical T- cCD3 +ve, CD7 +ve,CD2+ve, CD1a+ve, CD34
–ve
•Medullary T - cCD3 +ve, CD7 +ve,CD2+ve, CD1a-ve,
CD34 –ve , sCD3+ve
•Cortical T stage double +ve for CD4&CD8
64

65. T-Lymphoblastic leukaemia
GENETICS
•Clonal rearrangement of TCR gene
•20%cases with IgH gene rearrangement
•50-70%cases shows abnormal karyotype
•m/c involved gene include transcription factor TLX 1 &
TLX 3
•50% cases with mutation in NOTCH 1 & hCDC 4 gene
PROGNOSIS
Poor than B-ALL
•TLX1 positivity is favorable indicator
•NOTCH 1 mutation responsible for short survival
65

66. Prognosis in ALL
PARAMETERS GOOD POOR
WBC Low High(>50x10 9 /L)
GENDER Girls Boys
IMMUNOPHENOTYPE B-ALL T-ALL
AGE Child Adult Or Infant.
CYTOGENETIC Normal, hyperdiploid, Ph+,11q23rearrangements
.
TIME TO CLEAR BLAST
FROM BLOOD
< 1week >1week
TIME TO REMISSION <4weeks >4weeks
CNS DISEASE AT
PRESENTATION
Absent Present
MINIMAL RESIDUAL
DISEASE.
Negative At 1-3 Months Still Positive At 3-6
Months.
66

67. Risk Categories in ALL
Low Risk Intermediate Risk High Risk Very High Risk
Hyperdiploidy Age 1-10 year E2A/PBX Fusion BCR/ABL Fusion
with high TLC
TEL/AML1 fusion TLC<50,000/ cmm
without genetic risk
factor
T-ALL MLL Rearrangement
Age<1 year, >10 Year
and TLC>
50,000/cmm without
genetic risk factor
Induction Failure

68. DIFFERENTIAL DIAGNOSIS
 AML minimally differentiated
 Reactive lymphocytosis due to infection
 Small round cell tumor of the childhood that present
with marrow involvement
 Hematogones

70. ALL v/s REACTIVE LYMPHOCYTOSIS
 The atypical lymphocytes can be distinguished from
leukemic blast by
1. Relatively mature chromatin pattern
2. Low N:C ratio
3. Prominent nucleoli

71. ALL v/s SMALL CELL TUMOR OF
THE CHILDHOOD
 Immunophenotyping is helpful in arriving at correct
diagnosis

72. ALL v/s Hematogones
 Hematogones are the immature lymphoid cells
appearing like leukaemic blast
 May be seen in infections, following chemotherapy, &
bone marrow transplantation
 They can be differentiated from lymphoblast in having
higher N:C ratio, more homogeneous chromatin & no
discernible nucleoli

73. Bone marrow smear : lymphoid cells with high N:C ratio &
very homogeneous nuclear chromatin ,no or indistinct
nucleoli. These cells resembles the lymphoblast in ALL

76. INTRODUCTION
Acute leukemias of ambiguous lineage are those leukaemias that
show no clear evidence of differentiation along a single lineage
1. Acute undifferentiated leukaemia(AUL)
2. Mixed phenotype acute leukaemia(MPAL)
(9:22)(q34;q11.2);BCR-ABL1
t(v;11q23);MLL rearranged
B/myeloid, NOS
T/myeloid,NOS
Mixed phenotype acute leukaemia, NOS-rare types
Other ambiguous lineage
 Flocytometry is the preferred method for establishing diagnosis

77. Requirement for assigning more than one lineage to a single
blast population
MYELOID LINEAGE
Myeloperoxidase (flow cytometry, IHC or cytochemistry)
or
Monocytic differentiation (atleast 2 of the following : NSE, CD11c, CD14, CD64,
lysozyme
T LINEAGE
cCD23 (flow cytometry, IHC)
or
sCD23 (rare in mixed phenotype acute leukaemias)
B LINEAGE
Strong CD19 with atleast one of the following strongly expressed :CD79a, cCD22,
CD10
or
Weak CD19 with atleast 2 of the following strongly expressed :CD79a,Ccd22, CD10

78. Ac undiff
leukaemia
t(9:22)(q34;q11.2);B
CR-ABL1
t(v;11q23);MLL
rearranged
incidence Very rare MC in mixed Rare ,common in
children
Clinical features Similar as Ac.
leukaemia
similar similar
morphology No morphologic
features of myeloid
diff
Show dimorphic
blast population
Dimorphic:monobla
stic & lymphoblastic
cytochemistry MPO & esterase-ve -- --
immunophenotype Do not express B,T or
myeloid specific
marker
Blast meet criteria
for B & myeloid
lineage
CD19+,CD10-,CD15+
prognosis poor poor poor

79. B/myeloid,NOS T/myeloid,NOS
incidence Rare Rare
Clinical features similar similar
morphology May resemble ALL or have
dimorphic population
May resemble ALL or have
dimorphic population
cytochemistry MPO+ myeloblast or
monoblast,CD13+,CD33+,CD
117+,rare CD20+
MPO+ myeloblast or
monoblast,CD13+,CD33+,CD
117+,CD7+,CD5+,CD2+
immunophenotype Meet criteria for both B &
myeloid lineage
Meet criteria for both T &
myeloid lineage
prognosis poor poor

80. B/myeloid leukaemia with t(9;22)(q34;q11.2) small to large
blast with dispersed chromatin, prominent nucleoli &
moderate amount of pale cytoplasm

81. SUMMARY
 ALL is the most common leukaemia in childhood
 ALL with MLL rearrangement is the most common
leukaemia in infants
 Ac leukaemia of ambiguous lineage show no clear
evidence of differentiation along a single lineage
 The Dx of ambiguous lineage leukaemias is rest on
immunophenotyping, flowcytometry is the preffered
method

82. THANK YOU

83. SCORING SYSTEM OF ACUTE BIPHENOTYPIC
LEUKEMIA
POINTS B-LINEAGE T-LINEAGE MYELOID
2.0 CD 79a,CD22,u CD3 MPO
1.0 CD 10 CD 1 CD 13
0.5 TdT TdT,CD7 CD11b,CD11c
Score above 2 from two lineage is diagnostic of
biphenotypic leukemia