ALL (Exam III)

Question 1

Lymphocyte Ontogeny

Answer 1

Starts with a hematopoietic stem cell
- specific growth factor determines if it’s a B or T lymph

Antigen dependent matuaration
- B lymphocytic cells develop in BM
- T lymphocytic cells develop in the thymus (committed cells that migrated there from the BM)

Migrate to secondary lymphoid organs (lymph nodes, spleen and other)
- wait for antigen presentation

Antigen dependent maturation

Question 2

Lymph node structure

Answer 2

Going from outside in:

Cortex
- B lymphocytes populate outermost region for growth and development

Paracortex
- T lymphocytes

Medulla
- B lymphocytes and plasma cells

Question 3

Cases of ALL occur in

Answer 3

75% in children

Children have a higher rate of remission (85%) than adults

Question 4

WBC count in ALL

Answer 4

> 100,000 / ul

More often in T-ALL

Question 5

ALL symptoms

Answer 5

• Splenomegaly
• hepatomegaly
• thrombocytopenia
• bleeding
• nosebleeds
• bruises
• CNS Involvement

Question 6

ALL classification depends on

Answer 6

• Molecular and cytogenetics
• Immunophenotype
• Cytochemistry
• Morphology

Question 7

Most common ALL type

Answer 7

B cell ALL

Question 8

WHO ALL and Lymphoma classification

Answer 8

ALL
- >25% lymphoblasts in BM (out of all nucleated cells)

Lymphoma (LBL)
- equal or less than 25% lymphoblasts in BM
- Lymphoblastic leukemia process mass lesion elsewhere in the body

Question 9

Most common Lymphoma

Answer 9

T cell Lymphoma

Question 10

B cell ALL

Answer 10

• B cell lymphoblastic leukemia/lymphoma with recurrent genetic abnormalities
• B cell lymphoblastic leukemia/lymphoma, not otherwise specified

Question 11

ALL in children, what age is affected a lot?

Answer 11

1-4 years of age

Question 12

T cell Lymphoma

Answer 12

• Ealry T cell precursor lymphoblastic leukemia
• Natural killer cell (NK) cell lymphoblastic leukemia / lymphoma

Question 12

T cell Lymphoma

Answer 12

• Ealry T cell precursor lymphoblastic leukemia
• Natural killer cell (NK) cell lymphoblastic leukemia / lymphoma

Question 13

CALLA

Answer 13

common acute lymphoblastic leukemia antigen

CD10

Question 14

CD10 =

Answer 14

CALLA

Question 15

B lymphocyte development review

Answer 15

CHECK POWERPOINT

Question 16

Plasma cells

Answer 16

secrete antibodies

Question 17

memory B cell

Answer 17

Contains antibodies on cell surface

Question 18

CD19 and CD20, CD10(CALLA)

Answer 18

indicates B cell lineage. (ALL)

present when the cell is young

Question 19

TdT

Answer 19

cytochemistry is used to detect TdT

Question 20

CD19 + CD20

Answer 20

indicates immature stafes

Question 21

NOS (not otherwise specified group) of ALL

Answer 21

Lymphoblast morphology
- 2x size of resting mature lymphocyte
- condensed nuclear chromatin
- small scanty cytoplasm

OR/AND

• larger blasts
• dispersed nuclear chromatin
• Moderate Basophilic cytoplasm

Question 22

Immunophenotype in NOS ALL

Answer 22

• HLA-DR, CD10, CD19, CD20, CD34, cytoplasmic CD22, CD79a

Question 23

Cytochemistry NOS ALL

Answer 23

MPO neg, SBB Neg, TdT+

Question 24

Cytochemistry - Terminal deoxynucleotidyl transferase (TdT)

Answer 24

Stains terminal deoxynucleotidyl transferase (TdT) activity - **positive staining = Fluorescence** - Present in PreB and preT lymphoblasts, but not in mature lymphocytes

Question 25

TdT +

Answer 25

indicates ALL

Question 26

TdT -

Answer 26

indicates AML

Question 27

B cell ALL/LBL t(9;22)(q34;q11)

Answer 27

BCR-ABL1

Question 28

B cell ALL/LBL t(v;11q23)

Answer 28

KMT2A rearranges

Question 29

B cell ALL/LBL t(12;21)(p13;q22)

Answer 29

ETV6-RUNX1

Question 30

B cell ALL/LBL Hyperdiploidy

Answer 30

50-66 chromosomes in lymphoblasts

Question 31

B cell ALL/LBL Hypoploidy

Answer 31

<45 chromosomes in lymphoblasts

Question 32

B cell ALL/LBL t(5;14)(q31;q32)

Answer 32

IL3-IGH Eosinophilia

Question 33

B cell ALL/LBL t(1;19)(q23;p13)

Answer 33

TCF3-PBX1 Additional immunophenotype marker; cytoplasmic mu Similar to FAB L3 or Burkitt's classification

Question 34

B cell ALL/LBL BCR-ABL1-like

Answer 34

gene expression present but BCR-ALB1 fusion lacking

Question 35

B cell ALL/LBL intrachromosomal amplificaiton of chromosome 21 (iAMP21)

Answer 35

RUNX1 gene on chromosome 21 amplified, more or equal to 5 times

Question 36

T Lymphocyte development

Answer 36

REVIEW PPT

Question 37

T cell can become

Answer 37

CD4 = helper ce CD8 = cytolytic killer cell

Question 38

CD3 in T cells

Answer 38

mature T cells

Question 39

CD8 in T cells

Answer 39

suppressor cells

Question 40

CD4T cells

Answer 40

helper cells

Question 41

CD7 T cells

Answer 41

Pan T, immature

Question 42

T lymphoblastic leukemia/lymphoma cases:

Answer 42

More prevalent in adolescents than children Males>females

Question 43

Lymphoblast morphology T Lymphoblastic Leukemia

Answer 43

- medium size - prominent nucleoli; occasional nuclear clefting - moderate cytoplasm OR/AND - small size - HIGH N:C ratio - Scanty, indistinct cytoplasm

Question 44

Immunophenotype T lymphoblastic Leukemia/Lymphoma

Answer 44

Cytoplasmic **CD3, CD7** and variable CD1, CD2, CD4, CD5, CD8, CD10 - most identified as Prothymocyte Possible myeloid CD expression (CD13 and CD34)

Question 45

Cytochemistry T cell Lymphoblastic Leukemia/Lymphoma

Answer 45

MPO neg, SBB neg, **TdT+**

Question 46

Cytochemistry - Acid phosphatase

Answer 46

stains "acid phosphatase" activity - has 7 isoenzymes classified - **positive staning - orange/red precipitate** - Present in all hematopoietic cells - **T lymphocytes stain stronger than B lymophocytes** Used to differentiate lymphoblasts in suspected acute T cell lymphocytic leukemia

Question 47

NK Lymphoblastic Leukemia / lymphoma

Answer 47

Little is known about this disease Immunophenotype - **CD56 (NK cell marker)** - **Immature T cell markers present (CD2 and Cd7)** - Myeloid markers absent - B lymphoid markers absent Need to exclude Blastic Plasmacytoid Dendritic cell Leukemia prior to diagnosis

Question 48

TdT present in (B cell)

Answer 48

- stem cell - early pre B cell - Pre B cell

Question 49

CD10 and CD19 present in (B cell)

Answer 49

- early pre B cell - Pre B cell - B cell

Question 50

CD20 present in (B cell)

Answer 50

- pre B cell - B cell

Question 51

TdT present in (T cell)

Answer 51

- prothymocyte - cortical thymocyte

Question 52

CD7 presen in (T cell)

Answer 52

- prothymocyte - cortical thymocyte - medullary thymocyte - Mature T cell (peripheral)

Question 53

CD3 present in (T cell)

Answer 53

- cortical thymocyte - medullary thymocyte - mature T cell (peripheral)