ACUTE LYMPHOBLASTIC LEUKAEMIA.

1. ACUTE LYMPHOBLASTIC
LEUKAEMIA

2. OUTLINE
• INTRODUCTION – DEFINITIONS
• ETIOPATHOGENESIS
• CLINICAL FEATURES /PRESENTATION
• LABORATORY FEATURES
• LIGHT MICROSCOPY
• IMMUNOPHENOTYPING
• CYTOGENETICS
• ANCILLARY INVESTIGATIONS
• MANAGEMENT

3. Lecture objectives

4. INTRODUCTION
• Acute leukaemia is broadly divided into:
• AML
• ALL
• Acute leukaemia results from 2 complementary groups of mutations:
• Mutations conferring a proliferative/survival advantage
• Mutations impairing differentiation
• There is xtic accumulation of blasts in the marrow and/or PB
• Arbitrarily, Diagnosis is by finding >/= 20% blasts in BM or PB

5. B-lymphoblastic leukaemia/lymphoma
• SYNONYMS: B-cell ALL and B-cell LBL
• DEFINITIONS: 80-85% of ALL is of B-cell origin. Defined as a neoplasm
of precursors (lymphoblasts) committed to B-cell lineage.
• When the BM & blood are extensively involved – ALL is the
appropriate terminology.
• When the disease is confined to mass with absent or minimal
blood/BM involvement the appropriate terminology is B-LBL
• A patient can present with both.

6. ETIOPATHOGENESIS
• B-ALL arises in either
• HSC
• B-CELL PROGENIOTORS
• There are 2 factors involved:
• Genetic
• Environmental
• GENETICS: many ALL are thot to be congenital
• `shown evidence of genetic alteration in preleukaemic cells in-utero
• Genetic alterations are thought to be the initiating events
• A 2nd genetic alteration or 2nd hit is required for the overt disease to occur

7. • This 2nd hit and the leukaemia can occur many years after
• These genetic alterations include:
• Activated oncogenes
• Activated kinase activity
• Altered transcriptional regulation
• Patients with inherited genetic disorders have an increased incidence
and give evidence for the genetic pathogenesis
• Down syndrome
• NF-1
• Bloom syndrome
• Ataxia telangeictasia

8. THE ENVIRONMENT
• The following factors are linked to increased incidence
• Intra-uterine ionizing radiation
• Exposure to ionizing radiation
• Exposure to pesticides
• Post chemotherapy

9. CLINICAL ISSUES
• EPIDEMIOLOGY:
• B-ALL is the most common childhood malignancy.
• 75% present b4 age 6
• Slight M>F
• SITE:
• BM is the primary site. The blood is typically involved.
• CNS, LNs, liver, spleen and the testis are often involved
• The skin, soft tissue, bone and LNs are the primary sites in B- LBL.

10. PRESENTATION
• These result from tissue infiltration by leukaemic cells OR
• Insufficient production of normal blood cells in the marrow aka BMF
• BMF is defined by the presence of :
• Anaemia
• Neutropaenia
• thrombocytopaenia
1. CONSTITUTIONAL SYMPTOMS
1. FEVER
2. NIGHT SWEATS
3. WEIGHT LOSS

11. • Features of anaemia:
• Weakness
• Easy fatique
• Dyspnoea
• Pallor
• Features of neutropaenia/ reduced levels of normal Ig
• Fever
• Features of thrombocytopaenia-bleeding tendencies
• Purpura
• Epistaxis
• GIT bleeds
• Haematuria
• menorrhagia

12. • Features of tissue infiltration
• Enlargement of lymphoid tissues- lymphadenopathy, splenomegaly,
Hepatomegaly (there's frequent hepatosplenomegaly)
• Enlargement of the testis
• The periosteum: bone pain, arthralgias
• CNS: causing headaches, nausea, vomiting, visual disturbances, retinal
oedema or intraocular bleeding.

13. LABORATORY FEATURES
• FBC:
• Decreased Hb/PCV, RBCC, although cells remain normocytic/normochromic
• The total WBCC maybe high, normal or low, but with a PB neutropaenia
usually
• Platelet count is reduced (anaemia and thrombocytopaenia almost always
present)
• PBF shows immature WBC precursors (blasts)
• BMA/BMB reveal excess blasts in the marrow ( normal proportion of
primitive cells in the marrow is about 5%.

14. CLASSIFICATION AND DIAGNOSIS
• This is based on:
• Morphology under the light microscope
• The differentiation antigens expressed on immunophenotyping
• The chemical composition on cytochemistry
• Genetic characteristics ( karyotyping, molecular genetic analysis [PCR})

15. MORPHOLOGY
• PB/ BMA stained with Romanowsky dyes
• Malignant cells are classified based on the French, American, and
British (FAB) classification of AL
• FAB classification is especially useful in the absence of more advanced
techniques.
• Morphology is indispensable because it provides the platform for the
other investigations.
• The FAB divides ALL into 3 types: L1, L2, and L3

16. L1 BLASTS
• Small
• Scanty cytoplasm
• Condensed chromatin
• Indistinct nucleoli

17. L2 BLASTS
• Large
• Moderately abundant cytoplasm
• Fine/dispersed chromatin
• Variable nucleoli
• May have azurophilic granules

18. ANCILLARY TESTS:CYTOCHEMISTRY
• Blood and BMA sample spread, fixed on glass slides, exposed to
chemical stains and viewed under the microscope.
• Determining the chemical composition helps specify the lineage
• Cytochemical stains include:
• MPO
• SB
• Esterases
• PAS
• Leucocyte alkaline phosphate, acid phosphatase and TdT
• The PAS &acid phosphatase is positive in ALL (and erythroleukaemia).
It identifies the glycogen deposits in lymphoblasts and erythroblasts.

19. Immunophenotyping: Flowcy or IHC analysis
• Uses immunological markers to detect differentiation antigens
expressed by cells of a particular lineage.
• B-cell ALL:
• TdT, CD34, cCD79a, cCD22, CD19 for earliest stage blasts
• CD19
• CD22
• CD79a
• The above identify the B-cell lineage
• CD10 seen in intermediate stage blasts
• Mature stage blasts maybe negative for CD34
• Note: switch in IMPT is very common during therapy- gain or loss

20. CYTOGENETIC ANALYSIS
• Detects chromosomal translocations associated with specific entities:
• T(12;21) aka TV6-RUNX1 or ETV6-RUNX1. It is the most common in
paediatric ALL
• T(1;19)
• T(9;22) BCR-ABL1
• T(v;11q23) aka MLL rearrangement – common in neonates/infants
• T(5;14), associated with eosinophilia
• Hyperdiploidy
• hypodiploidy

21. OTHER ANCILLARY INVESTIGATIONS
• Blood uric acid and LDH levels
• S/E/U/C
• Coagulation tests
• Grouping and crossmatching of blood
• Viral studies- HBV & HCV, CMV, HIV; especially if this patient will
under go HSCT

22. T-LYMPHOBLASTIC LEUKAEMIA/LYMPHOMA
• SYNONYMS:
• T-ALL
• T-LBL
• DEFINITIONS:
• Neoplasms of precursor T-cells. And arises in HSC with immature T-
cell IMPT
• T-ALL and T-LBL were thought to be separate entities based on the
number of blasts in the marrow; But the current WHO classification
identifies them as a single biologic entity.

23. EPIDEMIOLOGY
• T-ALL
• ≈ 15% of all childhood ALL
• 25% of adult ALL
• And more common in adolescent males
• T-LBL
• ≈ 85% of all LBL
• More common in adolescent males

24. PRESENTATION- T-ALL
• Manifests commonly with high WBCC and circulating blasts
• Often concurrent mediastinal OR other tissue mass
• Lymphadenopathy, hepatosplenomegaly is common
• BM haemopoiesis is spared compared to B-ALL
• CNS involvement is more common than in T-LBL

25. PRESENTATION- T-LBL
• Rapidly growing anterior mediastinal mass
• Pleural and/or pericardial effusions are often present
• Respiratory symptoms and superior vena cava syndrome maybe seen
• BM involvement at diagnosis occurs in about 20%, and thus none or
minimal PB involvement

26. INVESTIGATONS
• SAME.
• T lymphoblasts are morphologically indistinguishable from B
lymphoblasts
• Flow cytometry
• TdT is usually expressed
• T-lymphoblasts variably express CD1a, CD2, CD5, CD7, cCD3 & sCD3
• They frequently co-express CD4 & CD8, but could express either one or the
other
• They may also co-express D10

27. CYTOGENETICS
• Structural abnormalities occur in about 50%, while numerical ABNs
are rare
• The structural abns that can occur include:
• Translocations involving TCR gene loci
• Translocations generating oncogenic chimeric proteins
• ABL 1 rearrangement
• Deletions causing loss of tumour suppressor genes
• Gene mutations

28. PROGNOSIS
• A very important factor in the management of the patient, especially
B-ALL/LBL.
• For B-ALL/LBL, overall prognosis is excellent. Cr is very high especially
in children
• NOTE:
• Infants with the MLL gene rearrangement have poor prognosis
• CNS and the testis are sanctuary for leukaemic cells, present treatment issues
and are common relapse sites

29. PROGNOSTIC FACTORS:CLINICAL &BIOLOGIC FACTORS
FACTORS FAVOURABLE UNFAVOURABLE
AGE 1 - 10 YEARS < 1 YEAR & >10 YEARS
SEX F M
WBCC < 50 X 10 9/L >50
IMPT COMMON TYPE OF ALL LACKS CD10 EXPRESSION
CNS DISEASE NO CNS DISEASE CNS DISEASE

30. CYTOGENETIC ABNORMALITIES AS PREDICATORS
FAVOURABLE
• HYPERDIPLOIDY (Greater than
50 chromosomes)
• T(12;21)
• INTERMEDIATE PROGNOSIS
• T(5;14)
• T(1;19)
• NORMAL KARYOTYPE
UNFAVOURABLE
• HYPODIPLOIDY (less than 45
chromosomes)
• T(9;22) or the BCR/ABL 1 fusion
• MLL rearrangement or the
t(4;11)
• Chromosomal amplifications

31. PROGNOSTIC PREDICATORS: RESPONSE TO
THERAPY
FAVOURABLE
• Day 7 or 14 BMA undetectable
blasts
• Morphologic remission after
induction
• Good PB response to a week of
systemic steroids, prior
chemotherapy with multiagent
UNFAVOURABLE
• BM blasts at day 7 or 14
• Requires 2 0r more cycles of
induction to achieve morpho.
Remission
• Poor response to steroids

32. PROGNOSIS – T-ALL/LBL
• The overall prognosis in children is poor compared to B-ALL
• But better prognosis is seen in adults than B-ALL

33. TREATMENT MODALITIES
• Intensive multidrug chemo, protocols is the mainstay
• Stratify patients based on the prognostic predicators as:
• Standard risk
• High risk
• Do this stratification at onset,
• and at end of induction based on response to therapy and MRD assessment
• Intrathecal prophylaxis with cranial radiation is a routine to prevent
CNS relapse
• Supportive care
• HSCT

34. Management- pre chemotherapy
• Information and counselling
• Resuscitation or supportive management especially for cytopaenias
• Transfusion of blood products
• Prevention and treatment of infections
• Prevention and treatment of biochemical abnormalities
• Hyperuricaemia/gout
• Hyperkalaemia
• Acidosis
• Drug toxicities
• Hydration
• Semen/ova cryopreservation

35. Management- Specific anti-leukaemic therapy
• Cytotoxic therapy employs combinations of drugs/multiagents with
different mechanisms of action
• It is standard to give agents in cycles in order to exploit the property
of normal healthy cells suffering less damage and recover earlier than
their malignant counterpart
• Giving until you the number of malignant cells is reduced to a point
below the level of detection by conventional (non-molecular biology)
techniques.
• This degree of response is known as remission

36. • Antileukaemic treatment is given in stages:
• Induction of remission
• Consolidation
• Intensification
• Maintenance
• CNS prophylaxis
• Remission induction, 2 cycles of:
• Vincristine
• Dexamethasone
• Daunorubicin
• L-asparaginase
• Cyclophosphamide
• cytarabine

37. Management- specific anti-leukaemic therapy
• Allogeneic HSCT is preferred
• Autologous is not effective
• The following may benefit:
• Failed achievement of complete remission after 5weeks of therapy
• T(9;22)
• T(4;11
• WBCC > 100