Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy. It is characterized by the proliferation of lymphoblasts in the bone marrow. ALL is classified into subtypes based on morphology, immunophenotyping and genetics. The disease is associated with genetic conditions and environmental exposures. Prognosis depends on factors like age, white blood cell count, cytogenetics and response to treatment. Immunophenotyping and detection of minimal residual disease help diagnosis and monitoring of ALL.

2. ACUTE
LYMPHOBLASTIC
LEUKEMIA

3. LEUKEMIA
• Leukemia are the neoplastic proliferation of
hemopoietic cells.
• Acute leukemias are defined as neoplsam
• AML - more than 20 % blast
• ALL- more than 25% blast.

4. ACUTE LYMPHOBLASTIC
LEUKEMIA
• Commonest form of malignancy in childhood.
• Peak incidence at 4 – 5 yrs of age.
• Acute onset with short history of duration.
• 85% are B cell , 15% are T cell.

5. PREDISPOSING FACTORS
• HEREDITARY
• ACQUIRED
• Ionizing radiations
• Therapeutic radiations
• Nuclear fallout
• Diagnostic Xrays
• Chemical agents
• Viruses

6. MECHANISM OF LEUKAEMOGENESIS
• Activation of a proto-oncogene to an oncogene when it
is translocated to a transcriptionally active site
• Formation of a chimeric transcription factor
• Formation of a fusion protein with enhanced tyrosine
kinase activity
• Activation of FTL3 receptor
• Inactivation of tumour suppressor gene pathway

7. SYMPTOMS
• FEVER
• FATIGUE
• BONE /JOINTS PAIN
• WEIGHT LOSS
• PURPURA AND BLEEDING MANIFESTATION
• LYMPHADENOPATHY
• HEPATOSPLENOMEGALY
• STERNAL TENDERNESS
• MEDIASTENAL MASS

8. FAB CLASSIFICATION
• Based on morphology and cytochemistry.
•
stain AML ALL
MPO + -
SBB + -
NSE
(non-specific esterase)
+ IN M4, M5 AND M7 -
PAS FINE + IN M6 , M7 + , BLOCK
ACID PHOSPHATASE - +, T ALL

9. FAB CLASSIFICATION
 ALL L1
 ALL L2
 ALL L3
 In childhood – L1 is the most common type
 In adults – L2 is the most common type

10. FAB classification
Morphology L1 L2 L3
1 Size of blast Small Large
heterogeneous
Large
homogenous
2 Cytoplasm Scanty Moderate Moderate,
intensely
basophilic
3 N/C Ratio High Lower Lower
4 Cytoplasmic vacuoles +/- +/- Prominent
5 Nuclear membrane Regular Irregular with clef
ting
Regular
6 Nucleoli Invisible /
indistinct
Prominent 1-2 Prominent 1-2

11. CRITICISM OF FAB CLASSIFICATION
1- It dose not include
• Immunophenotyping
• Cytogentics
• Molecular characteristics
2- immunological subtype of ALL
3-biphenotypic leukemia
4- Limited relevance to therapeutic or
prognostic implications.

12. WHO CLASSIFIACTION OF ALL (2008)
1-B lymphoblastic leukemia
2- B lymphoblastic leukemia
9; 22) , BCR ABL1
• t( v; 11q23) MLL rearangement
• t (12;21) ETV6-RUNX1
• With hypodiploidy
• With hyperdiploidy
• t (5;14) il3 –igh
• t ( 1;19) E2A-PBX1 (tcf3-pbx1)
3-T lymphoblastic leukemia/lymphoma

13. IMMUNOLOGICAL CLLASIFICATION
1- B ALL
•PRO B ALL
•EARLY PRE B ALL
•PRE B ALL
•MATURE B ALL
2- T ALL
3- MIXED LINEAGE ACUTE LEUKEMIA
4-Undifferentiated acute leukemia

14. IMMUNOLOGICAL CLLASIFICATION
SUBTYPE HLA DR TdT CD 10 cIg smIg
Pro B ALL +_ + - - -
COMMON ALL + + + - -
Pre BALL + - - + -
Mature B ALL - - - - +

15. T ALL
• PAS negative acid phosphatase positive
• CNS involvement and mediastenal mass
• CD3 ,2 and 7 positive

16. Scoring system for biphenotypic leukemia
B lineage T lineage Myeloid
CD 79a
CD 22.
CD 3 MPO
CD 10 CD 1 CD 13
TdT TdT, CD 7 CD 11b
CD 11c

17. Uncommon variants of ALL
• Small cell variant- blast cells are small and
may be mistaken for lymphocytes.
• Hand mirror variants- a subtype with
cytoplasmic protrusion .
• ALL with eosinophilia
• Granular cell ALL- The cells are large and
demonstrate azurophilic granulaes .

18. Hand mirror variants

19. DIAGNOSIS OF ACUTE LEUKEMIA
• Peripheral Blood smear
• Bone marrow aspiration smear
• Cytochemistry
• Immunophenotyping
• Cytogenetic analysis
• Molecular genetic analysis

20. PERIPHERAL BLOOD EXAMINATION
• Total leucocyte count raised , normal or low.
• Normocytic normochromic anaemia.
• Thrombocytopenia.

22. • Subleukemic leukemia-Total leukocyte count
is normal or low , but blast are seen in the
peripheral blood.
• Aleukemic leukemia- Blast are not seen in the
peripheral blood , but are demonstrable only
in bone marrow.

23. BONE MARROW EXAMINATION
• Hypercellular
• Normal hematopoietic elements diminished

24. ALL L1
Size – small.
Cytoplasm scanty basophilic.
N/C Ratio – high.
Nuclear membrane – regular.
Nucleoli – invisible or indistinct.

25. BONE MARROW SMEAR
BLAST

26. ALL L2
 Size of blast – large & heterogenous
 Cytoplasm – moderate
 N/C Ratio – lower
 Cytoplasmic vacuoles – variable
 Nuclear membrane – irregular with clefting
 Nucleoli – prominent ,1-2

27. BONE MARROW SMEAR

28. ALL L3
 Size of blast – large & homogenous
 Cytoplasm – moderate & intensely basophilic
 N/C Ratio – lower
 Cytoplasmic vacuoles – prominent
 Nuclear membrane – regular
 Nucleoli – prominent , 1-2

29. BONE MARROW SMEAR
LYMPHOBLAST WITH CYTOPLASMIC VACUOLES &
NUCLEOLI

30. STARRY SKY PATTERN

31. PAS STAIN
LYMPHOBLAST WITH BLOCK & COARSE GRANULAR STAINING

32. STAINS
METHYL GREEN PYRONINE OIL RED
O(VACUOLES)

33. IMMUNOPHENOTYPING
• Diagnosis and classification.
• Assessment of prognosis.
• Monitoring of minimum residual disease.

34. Molecular Genetics-
• Establishment of lineage-DNA analysis.
• Identification of translocation.
• Detection of relapse.
• Detection of minimum residual disease.

35. OTHER INVESTIGATIONS
• Lumbar puncture.
• Testicular biopsy.
• X-Ray chest.

36. DIFFERENTIAL DIAGNOSIS
• Leukemic phase of Non Hodgkins Lymphoma
• Reactive lymphocytosis due to infections
• Metastatic tumours in bone marrow
• AML

37. ALL Vs AML
ALL AML
Age Mainly children Mainly adults
Lymphadenopathy Usually present Usually absent
Hepatosplenomegaly +ve mild +ve mild
Gum hypertrophy -ve +ve in M4/M5
Skin infiltration -ve +ve in M4/M5
CNS involvement +ve in some +ve in some
Granulocytic sarcoma -ve +ve in few cases
Mediastinal mass +ve in T-ALL -
Associated DIC -ve +ve in M3
Serum muramidase Normal In M4/M5 (monocytic type)
Prognosis Good Bad

38. MorphologyLymphoblast Myeloblast
Nuclear chromatin Coarse Fine
Nucleoli 1-2 3-5
N:C ratio High High
Auer rod -ve +ve
Accompanying
cells
Lymphocytes Myeloid precursor
Myelo peroxidase -ve +ve
Sudan Black B -ve +ve
PAS stain Block positivity -ve in blast

39. AML ALL

40. PROGNOSTIC FACTORS
Factor Good prognosis Bad prognosis
Race White Black
Age 2-8 yrs <1yr.,adult, >10 yrs
Sex Female Male
Meningeal involvement - +
Lymphadenopathy, liver,
spleen
- Massively enlarged
Mediastinal mass - +
TLC <20x109
/L >50 x109
/L
Type of ALL L1 L2,L3
Cytogenetics Hyperdiploidy >50
chromosomes
Pseudodiploidy, t (4;11),t (9;22), BCR-ABL
fusion m RNA, MLL-AF4 fusion mRNA.
Immuno-phenotype B-ALL,CD 10+, Early pre-B
cell
T-ALL in children

41. Minimal residual disease detection
– ALL – B cell
– Cd20/cd10/cd19/cd45
– Cd9/cd34/cd19/cd45
– Cd58/cd10/cd38/cd19
– Cd20/cd10/cd19/cd34
– ALL –T cell
– TdT/CD5/CD3/CD7

42. • AML
• CD34/CD33/HLA-DR/CD45
• CD34/CD117/CD33/CD45
• CD115/CD117/CD33/CD34
• HLA-DR/CD117/CD33/CD34
• CLL
• CD20/CD79a/CD19/CD5

43. Factors Predisposing to Childhood
Leukemia
• GENETIC CONDITIONS
Down syndrome
• Fanconi syndrome
• Bloom syndrome
• Diamond-Blackfan
anemia
• Schwachman syndrome
• Klinefelter syndrome
• Turner syndrome
• Neurofibromatosis
• Ataxia-telangiectasia
• Severe combined
immune deficiency
• Paroxysmal nocturnal
hemoglobinuria
• Li-Fraumeni syndrome

44. • ENVIRONMENTAL FACTORS
• Ionizing radiation
• Drugs
• Alkylating agents
• Nitrosourea
• Epipodophyllotoxin
• Benzene exposure
• Advanced maternal age