Transcript 8-Acute Leukaemia

ACUTE LEUKAEMIA
by
DR. KAMAL E. HIGGY
CONSULTANT HAEMATOLOGIST
ACUTE MYELOID LEUKAEMIA
ETIOLOGICAL FACTORS
GENETIC DISORDERS
Congenital Defects
Marrow Failure Syndromes
Down syndrome
Bloom Syndrome
Monosomy 7 syndrome
Klinefelter Syndrome
Turner Syndrome
Neurofibromatosis
Congenital Dysmorphic Syndrome
Fanconi Anaemia
Dyskeratosis Congenita
Schwachman – Diamond Syndrome
Amegakaryocytic Thrombocytopenia
Blackfan – Diamond Syndrome
Kostmann Agranulocytosis
Familial Aplastic Anaemia
ACUTE MYELOID LEUKAEMIA
ETIOLOGICAL FACTORS
Environmental Factors
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Solvents (benzene)
Smoking
Ionizing radiation
Atomic bomb exposure
Nuclear power exposure
Medical radiation
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Non ionizing radiation
Chemotherapy
Alkylating agents
Topoisomerase II inhibitors
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Other drugs
Chloramphenicol
Phenylbutazone
Acute Myeloid Leukaemia
DEFINITION
Acute Myeloid Leukaemia (AML) is currently
defined by the FAB criteria.
The percentage of blasts, the presence of
cytochemical myeloperoxidase, the major cell types
present defined by morphology and esterase
cytochemistry & the immunophenotype define the 8
FAB subtypes
Acute Myeloid Leukaemia
CLINICAL FEATURES
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Increasing incidence with age. Median age at
diagnosis is 50 years.
Symptoms are due to marrow failure (anaemia,
infection, haemorrhage) or hyperleucocytosis.
Rarely presenting symptoms are due to chloromas
or CNS involvement.
Acute Myeloid Leukaemia
LABORATORY DIAGNOSIS
MORPHOLOGY
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Myeloblasts are usually medium sized with an eccentric
nucleus and open chromatin. Cytoplasm shows variable
basophilia. Few granules or Auer rods may be present.
Maturing granulocytes may be normal or show the
dysplastic features e.g. Psaudo Pelger (hypogranular bilobed
neutrophils).
Monoblasts are generally very large with abundant greyblue or basophilic cytoplasm. Nuclei are round or lobulated,
and are central in the cell. Fine azurophil granules may be
present but Auer rods are rarely, if ever, present.
Promonocytes and monocytes show abnormal nuclear
maturation, granulation and loss of basophilia.
Acute Myeloid Leukaemia
LABORATORY DIAGNOSIS
MORPHOLOGY (Cont…)
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Erythroid precursors may be normal or show varying
degrees of dyserythropoiesis.
Eosinophils may be present in varying numbers, with
normal or abnormal morphology. Specific abnormal
appearances are linked with cytogenetic abnormalities
(e.g. inv 16)
Basophils are rarely increased in AML, and if present show
abnormal or poor granule formation and nuclear maturation.
Megakaryocytes may be reduced or increased. Dysplastic
hyperlobated, hypolobated, multinuclear, small and blastic
forms may be present
Acute Myeloid Leukaemia
FAB Subtypes
M0-M5: >20% myelo/monoblasts by
morphology or immunophenotype.
M6:
>50% erythroid precursors, >20% blasts in non-erythroid cells.
M7:
>20% megakaryoblasts present.
Note:
Cytogenetics, molecular genetics, previous MDS or MPD, previous
chemo- or radiotherapy and the presence of trilineage
myelodysplasia do not have any place in the FAB system. All these
features which contribute to the definition of prognostically
important sub-groups is included in the new classification system.
Acute Myeloid Leukaemia
>20%
FAB Subtypes
>20%
>20%
>20%
>20%
>20%
M0
M1
M2
M3
M4
M5a
M5b
M6
M7
ACUTE MYELOID LEUKAEMIAS
WHO CLASSIFICATION
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Acute myeloid leukaemia with reccurent genetic
abnormalities
Acute myeloid leukaemia with t(8;21)(q22;q22); (AML1(CBFa)/ETO)
Acute myeloid leukaemia with abnormal bone marrow eosinophils
inv (16)(p13q22) or t(16; 16)(p13;q22); (CBFb/MYH11)
Acute promyelocytic leukaemia (AML with t(15; 17)(q22;q12)(PML/RARα) &
variants
Acute myeloid leukaemia with 11q23 (MLL) abnormalities
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Acute myeloid leukaemia with multilineage dysplasia
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Acute myeloid leukaemia and myelodysplastic syndromes,
therapy related
ACUTE MYELOID LEUKAEMIAS
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WHO CLASSIFICATION
Acute myeloid leukaemia not otherwise categorized
Acute myeloid leukaemia minimally differentiated
Acute myeloid leukaemia without maturation
Acute myeloid leukaemia with maturation
Acute myelomonocytic leukaemia
Acute monoblastic and monocytic leukaemia
Acute erythroid leukaemias
Acute megakaryoblastic leukaemia
Acute basophilic leukaemia
Acute panmyelosis with myelofibrosis
Myeloid sarcoma
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Acute leukaemia of ambiguous lineage
Undifferentiated acute leukaemia
Bilineal acute leukaemia
Biphenotypic leukaemia
Acute Myeloid Leukaemia
LABORATORY DIAGNOSIS
CYTOCHEMISTRY
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Myeloperoxidase (MPO): identify blast cells as myeloid.
Auer rods are detected twice as frequently as on
Romanowsky stains. Dysplastic neutrophils may be
negative. Eosinophil granules are always positive.
Monoblasts and promonocytes may be negative. Sudan
Black B gives identical results.
Myeloperoxidase (MPO)
Acute Myeloid Leukaemia
LABORATORY DIAGNOSIS
CYTOCHEMISTRY
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Chloroacetate Esterase (CAE) specifically identifies
cells of the granulocyte lineage, from the early
promyelocyte stage to mature neutrophils.
Chloroacetate
Esterase
Acute Myeloid Leukaemia
LABORATORY DIAGNOSIS
CYTOCHEMISTRY
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α -Naphthyl Acetate (Nonspecific) Esterase (ANAE)
stains monocytes and megakaryocytes at all stages
of maturation.
Nonspecific Esterase
Acute Myeloid Leukaemia
LABORATORY DIAGNOSIS
CYTOCHEMISTRY
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Periodic Acid Schiff (PAS) stains many cell
types. It is not lineage specific but the pattern
of staining may be helpful, e.g. positive
monoblasts, NRBC, megakaryoblasts…
Acute Myeloid Leukaemia
LABORATORY DIAGNOSIS
TREPHINE BIOPSY HISTOLOGY
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Helpful when there is severe cytopenia and a dry
tap, e.g. in megakaryoblastic AML.
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Useful for identifying megakaryocyte dysplasia and
dyserythropoiesis.
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Immunophenotyping is possible when the diagnosis
is in doubt.
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Not suitable for fine classification which is based on
percentages of cell types and cytological detail.
Acute Myeloid Leukaemia
LABORATORY DIAGNOSIS
FLOW CYTOMETRY
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Myeloid blasts express combinations of CD34, CD13,
CD33, CD117, HLA-DR, CD14, CD15. Glycophorin A and
CD42b identify erythroid and megakaryocyte lineage blasts
respectively.
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Essential to separate undifferentiated AML (M0) from ALL.
May need supplementation with APAAP staining for
cytoplasmic immunoreactive MPO.
Acute Myeloid Leukaemia
LABORATORY DIAGNOSIS
FLOW CYTOMETRY (Cont…)
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Essential for diagnosing biphenotypic leukaemias and
detecting aberrant (promiscuous) antigen expression.
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Can identify patient specific unique blast cell phenotypes.
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Can identify blasts of megakaryocyte, erythroid, monocyte
and granulocyte lineages.
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Can identify leukaemic contamination of 'remission'
marrow harvests.
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Can identify early relapse.
Acute Myeloid Leukaemia
LABORATORY DIAGNOSIS
MOLECULAR GENETICS
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The 3 major good prognosis translocations are all detectable
by RT-PCR, which can be used to detect up to 40% more
cases than are found by metaphase cytogenetics.
All translocations with cloned breakpoint genes are
theoretically detectable by RT-PCR.
Real time multiplex PCR may become available for routine
diagnosis.
RT-PCR is used for monitoring speed of response to
treatment and may be predictive for relapse
Acute Myeloid Leukaemia
LABORATORY DIAGNOSIS
CYTOGENETICS
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An abnormal karyotype is found in 50-60% of AML cases
at presentation.
t(15;17), t(8;21) and inv/del/t(16) are associated with
specific morphology, younger patients and a good
prognosis.
Complex karyotypes and abnormalities of chromosomes 5
and 7 are associated with older patients, trilineage dysplasia
and a poor response to treatment.
Other karyotypic abnormalities are prognostically neutral.
Acute Myeloid Leukaemia
LABORATORY DIAGNOSIS
IMMUNOHISTOCHEMISTRY / IMMUNOFLUORESCENCE
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APAAP staining for cMPO, cCD3 and cCD79
should be done in all cases of undifferentiated
acute leukaemia.
Immunofluorescent staining for nuclear PML
protein should be done in all cases of
suspected acute promyelocytic leukaemia. A
microparticulate pattern is diagnostic of
APML.
Acute Lymphoblastic Leukaemia (ALL)
Clinical Features
ALL can occur at any age but has a peak incidence
between 2 - 10 years. It is characterized by:
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bone marrow failure
lymphadenopathy
thymic enlargement in T-lineage ALL
bone pains which may be associated with
radiological changes and fractures
tendency to relapse in the CNS and testis.
Acute Lymphoblastic Leukaemia
Laboratory Diagnosis
FAB Classification
Acute Lymphoblastic Leukaemia
Laboratory Diagnosis
Acute Lymphoblastic Leukaemia
Laboratory Diagnosis
Morphology
Blast morphology is variable
 some are small with high nuclear / cytoplasmic
ratios and indistinct nucleoli (so-called L1 blasts)
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nucleoli and more abundant cytoplasm (L2).
 A third type (L3) shows large blasts with
moderately abundant highly vacuolated basophilic
cytoplasm
Blast morphology does not correlate with cell lineage
and cytochemistry is of little value.
Acute Lymphoblastic Leukaemia
Laboratory Diagnosis - FAB Classification
ALL (L1)
ALL (L2)
ALL (L3)
Acute Lymphoblastic Leukaemia
Laboratory Diagnosis
CYTOCHEMISTRY
PAS
Ac. Phos (T-ALL)
Acute Lymphoblastic Leukaemia
Laboratory Diagnosis
Flowcytometry
ALL is derived from precursor lymphocytes that are undergoing
antigen receptor gene (Ig and TCR) rearrangement.
B-lineage ALL
The precursor nature of the cells is established by demonstrating
lack of surface Ig, the presence of nuclear TDT and sometimes the
expression of CD34.
Sub classification is as follows:
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Pre-pre B-ALL: CD19+ CD10- cytoplasmic mu heavy chain negative.
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Common ALL: CD19+ CD10+ cytoplasmic mu present in <20% of cells
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Pre B-ALL: CD19+ CD10+ cytoplasmic mu present in >20% of cells
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Blasts of all subgroups will express cytoplasmic CD22 and CD79b.
Acute Lymphoblastic Leukaemia
Laboratory Diagnosis
Flowcytometry
T-lineage ALL
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The precursor nature of the cells is established by demonstrating
TDT and sometimes CD34 positivity and the lack of surface
TCR/CD3.
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T-cell lineage is demonstrated by the expression of CD7 and/or
CD1a.
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Expression of the other pan-T cell markers is variable.
Acute Lymphoblastic Leukaemia
Laboratory Diagnosis
CYTOGENETICS
Hyperdiploidy is common. A number of balanced translocations
have been identified in ALL:
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t(12;21) - this is the commonest translocation in ALL (30% of cases). It results
in the TEL-AML fusion gene and is primarily associated with the common
phenotype.
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t(9;22) - this is commoner in adults and is associated with a very poor
prognosis.
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t(4;11) - this translocation results in the MLL-AF4 fusion gene. It is
associated with pre-pre B-ALL and is associated with a poor prognosis.
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t(1;19) - associated with pre-B ALL and results in the formation of the E2APBX fusion gene.
These translocations are demonstrable by RT-PCR techniques.
TAL-1 deregulation is the commonest genetic abnormality in T-ALL. This
may occur as the result of the t(1;14) or more commonly due to chromosome
1p32 deletions.
Acute Lymphoblastic Leukaemia
PROGNOSTIC FACTORS
The following are poor prognostic factors in ALL:
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age <1 year and >10 years
male sex
CNS disease at presentation
high white cell count
t(9;22)
t(4;11)
hypodiploidy
Acute Lymphoblastic Leukaemia
OUTCOME AND THERAPY
The treatment of ALL consists of the following "phases":
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Remission induction - vincristine, prednisolone, daunorubicin,
asparaginase.
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Consolidation - various combinations of chemotherapeutic agents.
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CNS directed therapy - high dose systemic and intrathecal
methotrexate.
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Maintenance therapy - vincristine, prednisolone, mercaptopurine and
methotrexate for 2 years.
Childhood ALL is associated with 75% long term survival. Minimal residual
disease assessment using PCR based strategies appear to be able to predict
relapse although they are not yet in routine clinical use.
Allogeneic transplantation is the treatment of choice at relapse.
The outlook in adult ALL is poor with approximately 20% long-term
survivors. Allogeneic transplantation is advisable in first remission.