Acute Myeloid Leukemia with cytogenetic abnormality PARDIS NEMATOLLAHI,MD,ACP

Acute Myeloid Leukemia with cytogenetic abnormalityPARDIS NEMATOLLAHI,MD,ACP

Acute myeloid leukemia (AML) is a heterogeneous group of diseases that represent clonal proliferations of immature, nonlymphoid, bone marrow–derived cells that most often involve the bone marrow and peripheral blood and may

present in extramedullary tissues

the FAB classification remained the primary system used by most pathologists and hematologists for many years. The terminology of the FAB classification continues to be used,

but this system is now considered obsolete owing to its inability to accurately identify many prognostically

significant disease types.

Acute Myeloid Leukemia & Related Precursor Neoplasms

1. Acute myeloid leukemia with recurrent genetic abnormalities

2. Acute myeloid leukemia with myelodysplastic-related changes

3. Therapy-related myeloid neoplasms

4. Acute myeloid leukemia,NOS

5. Myeloid sarcoma

6. Myeloid proliferation related to Down syndrome

7. Blastic plasmacytoid dendritic cell neoplasms

Epidemiology The incidence of AML is approximately 3.5 cases per 100,000 per year. The median age at diagnosis is 67 years, and there is a slight

male predominance. The frequency of AML increases with age, with approximately 6% of cases occurring in children and adults younger than 20 years and more than 50% of cases occurring in patients 65

years of age and older.

EtiologyThe cause of many cases of AML is unknown, particularly those arising in children and young adults. A subset of AML arises from a preexisting myelodysplastic syndrome (MDS) or is a secondary leukemia related to prior therapy for a nonleukemic disorder. AML occurs more commonly in patients with some preexisting genetic disorders, including Fanconi’s anemia and Down syndrome.

Current Approach to Diagnosis of ALs:Practice of Multidisciplinary Correlations

Clinical history

Morphology (architecture and cytology)

Immunophenotyping

FC(Multiparameter flow cytometric methods), IHC, and

cytochemistry

Cytogenetic/ FISH

Molecular genetic

Acute Myeloid Leukemia & Related Precursor Neoplasms

1. Acute myeloid leukemia with recurrent genetic abnormalities

2. Acute myeloid leukemia with myelodysplastic-related changes

3. Therapy-related myeloid neoplasms

4. Acute myeloid leukemia , NOS

5. Myeloid sarcoma

6. Myeloid proliferation related to Down syndrome

7. Blastic plasmacytoid dendritic cell neoplasms

Acute myeloid leukemia with recurrent genetic abnormalities

This group is characterized by recurrent genetic abnormalities of prognostic significance

The most common:

t(8,21)

inv(16) or t(16,16)

t(15,17)

t(9,11)

t(6,9)

inv(3)

t(1,22)

Are considered as acute leukemia without regard to blast cell countAre considered as acute leukemia without regard to blast cell count

Many of these diseases have characteristic morphological & immunophenotypic features

Acute myeloid leukemia with t(8,21)AML with t(8;21)(q22;q22) has distinctive morphologic and immunophenotypic findings that correlate well with a specific cytogenetic abnormality Generally show maturation in neutrophilic lineagemeeting the criteria for M2 AML in the FAB classification(Found in 10% of the prior acute myeloblastic leukemia with maturation (M2) of FAB classification)

Acute myeloid leukemia with t(8,21),cont

*Morphology & Cytochemistry: Large blasts with abundant basophilic cytoplasm , often containing azurophilic granules(The blasts in the bone marrow have cytoplasmic hofs , occasional Auer rods, and occasional large, salmon-colored granules)

Some blasts show very large granules(pseudo-chediak-higashi ) Auer rods frequently found Variable dysplasia is noted in myeloid series , uncommon in other cell lines Eosinophil precursors frequently increased but not abnormal Basophils and/or mast cells sometimes increased Monocytic series usually minimal or absent

Acute myeloid leukemia with t(8;21)A, Blasts show a variable number of granules, suggesting cell maturation. One blast contains thin Auer rods. B, Perinuclear hofs (green arrows) and large pink granules (black arrows) are characteristic features of this type of AML.

Chediak-Higashi–like granules

On this high-power view, blasts are seen with some maturing myeloid elements as demonstrated by the appearance of granules. There is, however, a maturation arrest as PMNs and bands are not present

Centrosomes are evidence of myeloid differentiation


Immunophenotyping:Characteristic immunophenotype : high intensity expression of CD34,HLA-DR,MPO,CD13,weak CD33Sometimes population of blasts showing maturation asynchrony(co expression of CD34,CD15)Frequently express lymphoid markers CD19,PAX5,cCD79aSome cases weak TdT expressionSometimes CD56 expression


Prognosis and predictive factors:Good response to chemotherapyHigh complete remission rate and long term disease-free survivalCD56 with adverse prognosis

The differential diagnosis 1-APL 2- mixed phenotype acute leukemia 3-MDS 4- Regenerative changes that include the effects of growth factors

Acute myeloid leukemia with t(16,16) or inv(16) Definition:Is an AML that usually shows monocytic and granulocytic differentiationCharacteristically with abnormal eosinophil component in the BM, meeting the criteria for AML M4EO in the FAB classification

Acute myeloid leukemia with t(16,16) or inv(16),cont

Morphorphology and Cytochemistry:

In addition to usual morphological features of acute myelomonocytic leukemia,variable number of eosinophilia at all stages of maturation

The eosinophilic granules are often larger than those normally present in immature eosinophils,purple violet in color,some obscure the cell morphology,mature eos show nuclear hyposegmentation

Auer rods may observed in myeloblast

At least 3% of blasts show MPO reactivity

PB such as acute myelomonocytic leukemia , abnormal and increased eos

Acute myeloid leukemia with inv(16): A and B, Both cases show blasts with monocytoid nuclear features and abundant cytoplasm. One leukemia (A) exhibits numerous eosinophil precursors, some of which have the characteristic large basophilic granules. The other (B) shows only one abnormal eosinophil.

AML with inv(16) The dysplastic eosinophil precursors are shown at a higher magnification. Note both eosinophilic and basophilic granules are present in the cytoplasm of these cells.

Acute Myeloid Leukemia with inv 16 Acute myelomonocytic leukemia with abnormal eosinophils (arrow).

Acute Myeloid Leukemia with inv( 16 )The arrow marks an abnormal immature eosinophil found in the bone marrow of a patient with an acute myeloid leukemia with inv (16)


Immunophenotype:Complex immunophenotype with multiple blast population:1-Immature blasts with CD34 and CD1172-blasts differentiating towards granulocytes(CD13,CD15,CD56,MPO)3-blasts differentiating towards monocytes(CD14,CD4,CD64,CD11b,CD11c)4-Maturation asynchrony5-Aberrant expression of CD2

The differential diagnosis 1-myelomonocytic types of AML, NOS 2-Reactive monocytic proliferations 3-CMML


Prognosis and predictive factors:Longer complete remissionOlder patients have decreased survival

Acute promyelocytic leukemia with t(15,17)

Definition:APL is an AML in which abnormal promyelocytes predominateBoth hypergranular or typical and microgranular or hypogranular types exist

Epidemiology:5-8% of all AMLCan occur in any age , dominantly adults in mid life

Acute promyelocytic leukemia with t(15,17),cont

Clinical features:Frequently associated with DICIn microgranular APL,the leukocyte count is very high


Morphology and Cytochemistry:Nuclear size and shapeCytoplasmic granules,Faggot cells are characteristicMPO reactionCases of microgranular APL are characterized by distinct morphological features such as paucity or absence of granules, and predominantly bilobed nuclear shapeCases of microgranular may misdiagnosed as acute monocytic leukemia:

1-small number of typical promyelocytes and faggot cells

2-marked elevated leukocyte count

3-strong MPO reaction

Acute promyelocytic leukemia (FAB M3), bone marrow aspirate. The blasts are relatively monomorphous and show heavily granulated cytoplasm without Auer rods (compare with acute myeloid leukemia with maturation). Karyotyping showed t(15;17).

Faggot" cell in acute promyelocytic leukemia

A "faggot" cell present on the peripheral smear from a patient with acute promyelocytic leukemia is shown. The cytoplasm contains multiple Auer rods, singly and in bundles.

“Flaming” promyelocyte .Abnormal promyelocyte with disintegrating cytoplasm which, in turn, liberates Auer rods and granules into the surrounding marrow. These "flaming" promyelocytes are one of the characteristic cells found in APL.

Acute promyelocytic leukemia (FAB M3), bone marrow aspirate. Numerous blasts are present, showing folded and lobated nuclei and abundant cytoplasm containing Auer rods and granules. Karyotyping showed t(15;17).

APL Some abnormal promyelocytes have a distinct folding pattern to the nucleus as shown by the cell marked with the arrow.

AML-M3, Hypogranular Variant At higher magnification of the cells shown on the previous slide, the nuclear convolutions are more apparent. Azurophilic granules are present in the cell on the left. A peinuclear hof can not be seen in any of the hypogranular promyelocytes.

Acute promyelocytic leukemia (FAB M3), bone marrow aspirate. The blasts are very large, with lobated nuclei, fine dust-like cytoplasmic granules, and numerous Auer rods. Karyotyping showed t(15;17).

Acute promyelocytic leukemia (FAB M3), bone marrow clot. The marrow is replaced by a diffuse infiltrate of blasts with abundant, heavily granulated cytoplasm.


Immunophenotyping:Absence of HLA-DR and CD34(microgranular may express dim HLA-DR and commonly dim CD34Bright expression of CD33Heterogenous expression of CD13Many cases CD117Commonly CD64Microgranular shows CD34 & CD2 expression

Differential diagnosis: Hypergranular variant:

Agranulocytosis and maturation arrest at promyelocyte

Regenerative hyperplasia

AML without maturation with negativity for CD34 and HLA-DR(next slide)

Microgranular variant:

AML with monocytic differentiation

HLA-DR and CD34 negative AML without maturation,shows fish mouth deformity or cup like nuclear inclusion

Arrow marks "thumbprinting" which is characteristic of myeloid blasts.


Prognosis & predictive factors:APL has a particular sensitivity to ATRA which acts as a differentiating agentPrognosis in APL treated optimally with ATRA is more favourable than for any other AML cytogenetic subtype

Acute myeloid leukemia with t(9,11),MLLIs usually associated with monocytic differentiationMay occur in any age ,but is more common in childrenMay presented with DIC or extramedullary myeloid sarcoma

Acute myeloid leukemia with t(9,11),MLL,cont

Morphology & cytochemistry:There is a strong association with acute monocytic and acute myelomonocytic leukemia Monoblasts and promonocytes show strong positivity for non specific esteraseMonoblasts are negative for MPOPromonocytes may show weak reactivity with MPO

Acute myeloid leukemia with t(9;11)The morphologic appearance is variable. A, This case shows abundant basophilic cytoplasm, suggestive of monocytic differentiation. B, This case shows blasts with a more myeloblastic appearance, including some cells with granules. Although myelomonocytic or monocytic features are most common, there are no specific morphologic features of this translocation.


Immunophenotype:Cases of AML with MLL in children:Strong CD33, CD4 , HLA-DRLow CD 13 , CD 14 ,CD34Cases of AML with MLL in adults:Express some markers of monocytic differentiation CD4 , CD14 , CD64 ,CD11b ,CD11cVariable expression of immature markers,CD34 , CD117


Prognosis and predictive factors:Has intermediate survival

Acute myeloid leukemia with t(6;9)Is an AML with or without monocytic featuresis often associated with basophilia and multilineage dysplasia

Acute myeloid leukemia with t(6;9),cont

Morphology and cytochemistry:May shows morphologic and cytochemical features of any type of FAB subtype of AML other than APL and acute megakaryoblastic leukemiaMarrow and PB basophiliaMost cases show granulocytic and erythroid dysplasia and less common megakaryocytic dysplasiaRing sideroblast may be seen

Acute myeloid leukemia with t(6;9)Blast cells exhibit variable morphology but are often associated with admixed basophils (arrows). A, Blasts with monocytic features. B, Myeloblasts without maturation and dysplastic erythroid precursors.


Immunophenotype:Blasts consistently express MPO,CD13,CD33,CD38,HLA-DRMost cases express CD117 , CD34 , Half are TdT positive

Differential diagnosis: 1-AML with myelodysplastic related changes 2-Blast transformation of CML


Prognosis and predictive factors: Poor prognosis Elevated WBC Increased BM blast

Shorter overall survival

Acute myeloid leukemia with inv(3)May present de novo or from prior MDSNormal or elevated plt count BM atypical hypermegakaryosisMultilineage dysplasia

Morphological findings

Acute myeloid leukemia with inv(3),cont

Clinical features:Anemia and normal to elevated plt countMay have HSMLAP is uncommon


Morphology and cytochemistry:

May show any type of FAB classification of AML other than APL

Blood findings: normal to elevated plt count

Giant and hypogranular plt

bare megakaryocyte nuclei

Hypogranular PMN with pseudo pelger huet anomaly

BM findings: Atypical hypermegakaryosis

Dyserythropoietic and dysgranulopoiesis are common

Marrow eos , bas & mast cells may increased

Acute myeloid leukemia with inv(3)(q21q26.2) .A, Increased blasts with mono- and bilobed megakaryocytes are typical of this disorder. B, Distinctive hypolobated megakaryocytes are apparent on the biopsy specimen.


Immunophenotyping:Blast cells express CD13 , CD33 , HLA-DR , CD34 , CD38Some aberrantly express CD7Some express CD41 , CD61


Prognosis and predictive factors:

Is an aggressive disease

Acute myeloid leukemia(megakaryoblastic) with t(1;22)Is an AML showing maturation in the megakaryocyte lineageIs uncommon(<1% of all AML)Most commonly occurs in infants without Down syndromeF>M

Acute myeloid leukemia(megakaryoblastic) with t(1;22),cont

Morphology & cytochemistry:Similar to acute megakaryoblastic leukemia , NOSSmall and large megakaryoblast(cytoplasm is basophilic , often agranular,may show bleb or pseudopod)Micromegakaryocytes are commonReticulin and collagen fibrosisBlasts are negative for MPO

Acute myeloid leukemia (megakaryoblastic) with t(1;22).A, Hemodilute aspirate shows rare blasts with basophilic cytoplasm and blebbing. B, Core biopsy shows blasts and atypical megakaryocytes.

Acute myeloid leukemia(megakaryoblastic) with t(1;22),cont

Immunophenotyping:CD41 , CD61Myeloid associated markers may be positive,CD13 , CD33Often negative:CD34 , CD45 , HLA-DRNegative MPO , TdT

Prognosis and predictive factors:

Poor

References1-WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues,4th Edition,2008

2-Pathology of Bone marrow and Blood cells,Diane C.Farhi,2nd Edition,2009

3-Flowcytometry in evaluation of hematopoietic neoplasms,Sindhu Cherian,2012

4-Hematopathology,Elaine S. Jaffe ,2011

5-Henry,s Cinical Diagnosis and Management by Laboratory Methods,22nd Edition 2011

Documents

Acute Myeloid Leukemia with cytogenetic abnormality PARDIS NEMATOLLAHI,MD,ACP