Musm Hematology

Front 1

A: analogous to blood smear, can examine individual cells and determine M:E ratio and presence of myeloid maturation

B: 3D section is fixed and sliced before being placed on a slide, can examine marrow architecture and overall cellularity

Back 1

Bone Marrow Aspirate vs Biopsy

Front 2

Acute leukemias

Back 2

Neoplastic cell: very immature, very early in the lineage.

Precipitous onset

Effacement and replacement of the normal hematopoietic elements of the bone marrow result in pancytopenia and fatigue, bruising, bleeding, infections

Infiltration of other tissue by the neoplastic cells may be responsible for some signs or symptoms.

Without treatment, survival measured in days or weeks.

Front 3

Distinguish by clinical and microscopic findings, cytochemistry, cytogenetics, immunophenotype

A: Neoplastic cell shows features of commitment to the myeloid/ erythroid/ megakaryocytic/ monocyte lineage, Acute: subtypes classified by cytogenetics and morphology, Chronic: several related but distinct disorders.

B: Neoplastic cell has features of commitment to lymphoid lineage, Acute: T vs B lineages; B has several subtypes, Chronic: usually B, but other types exist.

Back 3

Myeloid vs Lymphoid Leukemias

Front 4

Chronic Leukemias

Back 4

Insidious onset
Diagnosis may even be serendipitous
Survival in the absence of treatment usually measured in years.
Neoplastic cells show differentiation, and in some cases, ~function

Front 5

Chronic Myeloproliferative Disorders

Back 5

Clonal disorders: transformed pluripotent stem cell or multipotent progenitor cell
One cell line gets a “proliferative advantage” but multiple lineages may derive from transformed cell.
Progeny of transformed cell mature relatively normally.
Hematopoiesis is effective, at least for a while

Front 6

Most common CMPDs

Back 6

CML
Polycythemia rubra vera
Primary myelofibrosis/Agnogenic Myeloid Metaplasia
Essential Thrombocytosis

Front 7

CML

Back 7

Clonal stem cell disorder
t(9;22) - BCR/ABL fusion protein has constituitive tyrosine kinase activity, deregulating signal transduction pathways - leads to abnormal cell cycling, inhibition of apoptosis, and increased proliferation of cells
Characterized by 3 sequential phases: Chronic, Accelerated, Blast-crisis - each is progressively more resistant to therapy

Front 8

CML; bone marrow aspirate

Back 8

note all stages of the granulocyte family tree are present; during the stable phase, the neutrophilic myelocytes are the most numerous

Front 9

CML; peripheral blood smear

Back 9

small number of blasts and promyelocytes seen; sometimes can look like reactive leukocytosis but other Dx tests (LAP, 15 etc) can help establish Dx

Front 10

Leukocyte Alkaline Phosphatase

Back 10

Enzyme found in mature neutrophils
Activity is increased in neutrophilias related to infection and inflammation
Activity is increased during pregnancy
Activity is LOW in CML
Activity normal or increased in other CMPDs
Red staining indicates LAP activity. Score 100 cells: 0, 1+, 2+, 3+ or 4+ based on intensity

Front 11

Imatinib

Back 11

"designer" treatment for CML
Binds to ATP-binding site and inhibits BCR/ABL fusion protein activity

Front 12

Clinical course of CML

Back 12

Chronic or stable phase: Relatively asymptomatic, +/- splenomegaly, fatigue, weight loss, bleeding
Accelerated phase: Loss of response to therapy, +/- fevers, bone pain, increased weight loss, increasing splenomegaly, increasing #s of blasts in marrow and blood.
Blast crisis: 20% or more blasts in marrow and/or peripheral blood

Front 13

Blast crisis

Back 13

Blast crisis is defined as 20% or more blasts in the marrow or peripheral blood

Front 14

Blast crisis

Back 14

Blast crisis is defined as 20% or more blasts in the marrow or peripheral blood

Front 15

A: Philadelphia chromosome
Decreased LAP score.
Accelerated phase and blast crisis ~inevitable in absence of treatment

B: Mutations of JAK2 frequent.
LAP score normal or increased.
Progression to AML varies and is NOT inevitable

All can be complicated by hepatosplenomegaly and marrow fibrosis

Back 15

CML vs. other CMPDs

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CMPDs

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CML
Polycythemia vera
Essential thrombocytosis
Myelofibrosis (Primary, Post-P vera, Post-thrombocytosis)

Front 17

Essential thrombocytosis

Back 17

Increased platelets in blood
Increased megakaryocytes in bone marrow

Front 18

Idiopathic (primary) myelofibrosis

Back 18

Front 19

Extramedullary hematopoesis

Back 19

Production of blood cells outside the confines of the bone marrow
Most commonly spleen, but also liver, skin, lymph nodes
Not seen in acute leukemias or lymphoproliferative disorders
May develop in severe chronic hemolytic anemias, especially beta thalassemia major
RBCs have "teardrop" morphology

Front 20

Back 20

A: normal spleen

B: spleen with extramedullary hematopoesis from a Pt with idiopathic myelofibrosis

C. Spleen from Pt in 'B'

Front 21

Polycythemia rubra vera

Back 21

Erythropoietin level will be low in P vera. In patients with secondary polycythemias, erythropoietin level will be high.
Despite the erythroid lineage having the “proliferative advantage” in P vera, there are also abundant megakaryocytes evident in this bone marrow specimen

Front 22

Lab features of P vera, Essential thrombocytosis, and idiopathic myelofibrosis

Back 22

In P vera the increased Hct is remarkable.
In Essential Thrombocytosis, the platelet count is remarkable.
In Idiopathic (Primary) Myelofibrosis, the marrow is characteristically replaced by fibrous tissue; extramedullary hematopoiesis occurs. Clues on peripheral smear include tear drop RBCs, nucleated RBCs and immature granulocytes.
Remember, all of these (and CML) may be complicated by marrow fibrosis. But, it would appear that the marrow fibrosis occurs sooner and more predictably in Idiopathic Myelofibrosis

Front 23

95% of P vera have what mutation?

Back 23

JAK 2 mutation - constituitively active, acts as though receptor has EPO bound

Front 24

Acute Myeloid Leukemia

Back 24

remarkable buffy coat; myeloid lineage - greenish color due to heme in MPO

Front 25

Why perform leukophoresis pre-chemo treatment for AML?

Back 25

reduce burden of neoplastic cells

Front 26

What drug might you give when performing leukophoresis?

Back 26

allopurinol

Front 27

Why do you want to reduce the burden of neoplastic white cells in AML pre-chemo?

Back 27

improved perfusion of small vessels, reduced debris from post-chemo "die-off" preventing DIC, less nucleic acid metabolites to form uric acid - no gout-related tissue damage

Front 28

2 models of how AML clones develop

Back 28

1. a previously normal hematopoetic stem cell acquires a sequence of mutations that alter how its growth is controlled as well as interfere with the ability of its progeny to differentiate
2. mutations arising in an at least partially differentiated cell restore gene-expression patterns that allow this cell to reacquire the unique self-renewal properties of stem cells while also interfereing with the ability of its progeny subsequently to differentiate

Front 29

AML

Back 29

neoplastic blast cells appear homogenous and undifferentiated, actually they are a heterogenous collection that recapitulate the hierarchy of early precursor cells in blood cell differentiation

only a small subgroup retains the capacity to proliferate and self renew - leukemic stem cells - dependent on Wnt

Front 30

Wnt pathway signaling in AML

Back 30

pathway inhibits destruction of beta-catenin
beta-catenin translocates to nucleus and complexes with TCF, promoting transcription of c-Myc and cyclin D1

Front 31

AML risk factors

Back 31

radiation
chemotherapy with alkylating agents (5q-, 7q-)
chemotherapy with topo II inhibitors: MLL gene translocation
benzene
congenital conditions associated with genomic instability
myelodysplastic syndrome or CMPD

Front 32

2 methods of classifying AMLs

Back 32

FAB (french american british)

WHO

Front 33

FAB scheme for AML classification

Back 33

8 categories: M0-M7
Based on degree of maturation and lineage
Uses light microscopy, cytochemistry, immunophenotype, cytogenetics to classify

Front 34

WHO scheme for AML classification

Back 34

special categories based on specific cytogenic findings that have particular prognostic importance
t(15;17), Inv16, t(8;21), t(11q23;v)

Front 35

WHO (broad) categories of AML

Back 35

AMLs with well defined genetic aberrations
AMLs associated with myelodysplastic syndromes
AMLs following chemotherapy
AMLs not otherwise specified

Front 36

Auer rods

Back 36

aberrant primary granules with MPO activity, not specific for a particular FAB M type or genetic finding, but indicate a NON-lymphoid leukemia and neoplastic process

Front 37

FAB M0

Back 37

No single defining cytogenetic abnormality
Myeloperoxidase (MPO) negative, no Auer rods
Expresses early myeloid antigens on immunophenotype
Prognostic category: intermediate
Remember: TdT negative

Front 38

FAB M1

Back 38

No single defining cytogenetic abnormality
Some cells MPO+
Some cells may contain Auer rods
Prognostic category: Intermediate

Front 39

FAB M2

Back 39

Commonest AML
At least two prognostic sub- categories:
t8;21 positive associated with favorable prognosis.
t8;21 negative: intermediate prognosis
Blasts & some more mature cells: a few promyelocytes, myelocytes, maybe even later ones
Blasts MPO + and may contain Auer rods

Front 40

FAB M3

Back 40

t15;17 defines the category
Predominant cell is the promyelocyte
Neoplastic promyelocytes contain thromboplastin-like substance in granules: DIC is additional problem.
Prognostic category: Intermediate

Front 41

FAB M3

Back 41

The t15;17 splits the retinoic acid receptor on 17 and inserts the PML gene from 15. A fusion protein results that suppresses retinoic acid receptor gene expression, thereby interfering with normal myeloid maturation.
Treatment includes administration of all-trans -retinoic acid

Front 42

FAB M4

Back 42

Neoplastic population: a mixture of immature cells with myeloid features (myloperoxidase (MPO) + and chloroacetate esterase +) and cells with monocytic features (non-specific esterase +).
Prognostically heterogeneous
Includes favorable, intermediate and poor sub-categories.
inv16 often found

Panel C shows a cytochemical stain for MPO activity (black granules); two blasts are positive, two negative.
Panel D shows a double esterase stain where myeloid cells stain red and monocytic cells are black.