Hematological Malignancies: B-cell

Question 1

What is a common marker between B cells and T cells?

Answer 1

Tdt

Question 2

Name the defining PLASMA CELL surface markers.

Answer 2

CD38
CD138
CD20(-)

Question 3

What cell surface markers can you use to differentiate a population of proliferating T-cells from B-cells?

Answer 3

B-Cells:
CD20
CD19
CD10

T-cells:
CD3
CD4
Any C less than 10

Question 4

You have a clonal expansion of IMMATURE B-CELLS. What cell surface markers will be detected?

Answer 4

TdT
CD10
CD20
CD19

Question 5

There is a clonal expansion of Mature B-cells (NOT plasma cells). What cell surface markers indicate this?

Answer 5

CD19
CD20
CD10

(No TdT)

Question 6

You apply a CD5 monoclonal antibody to a paraffin-embedded tissue sample of a lymph node. What cells will you tag and where in the lymph node will you see them?

Answer 6

CD5 is less than 10, so you’ll be tagging T-cells!

They will be visualized in the paracortex.

Question 7

Where are the 3 Ig promoters located in the human genome?

Answer 7

IgH (14q32)

Ig lambda (22q11)

Ig kappa (2p12)

Question 8

If the bloodstream is the main physical location of a cancer, what is it called?

Answer 8

Leukemia

Question 9

If the lymphoid tissues are the main physical location of a cancer, what is it called?

Answer 9

Lymphoma

Question 10

Burkitt’s Lymphoma predominately affects what tissue?

Answer 10

The GI tract - MALT

Question 11

CLL/SLL stands for what and is derived from what type of cell?

Answer 11

Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma

is derived from Memory B-cells.

Question 12

What is peripheral smear buzzword for CLL/SLL?

Answer 12

SMUDGE CELLS

Small lymphocytes with little cytoplasm.

Question 13

Name the 3 sites you’ll find CLL/SLL.

Answer 13

Peripheral blood > bone marrow > lymph nodes

Question 14

What is the morphology of a lymph node with CLL/SLL?

Answer 14

Peudofollicular (GOOGLE THIS)

Question 15

What is the odd Immunophenotype of CLL/SLL?

Answer 15

CD20+ (weak)

CD5+ (usually a T-cell marker)

Question 16

If CLL/SLL (Chronic lymphocytic leukemia/Small lymphocytic lymphoma) has a certain immunophenotype, its prognosis is bad. What are these 2 markers?

Answer 16

Zap 70

CD38

These are markers of somatic hypermutation status.

Question 17

Genetics of CLL/SLL:

What is the prognosis for a 13p deletion?

17p deletion?

Answer 17

13p deletion only = good

17p deletion (p53) = BAD

Question 18

If you see 17p deletion, what should you automatically think?

Answer 18

p53 deletion - BAD PROGNOSIS

Question 19

What is CLL easily confused with and how can you tell them apart?

Answer 19

CLL is easily confused with MANTLE CELL LYMPHOMA.

Difference: There are no proliferation centers in the lymph nodes in MCL

Smears are the same (smudge cells)

Immunophenotype:
CLL- CD20 weak
CD5+

MCL- CD20 strong
CD5+
CD23 -

Question 20

Describe the lymph node appearance in MCL (Mantle Cell Lymphoma)

Answer 20

Homogenous effacement. “Starry sky” appearance.

Question 21

What genetic event causes Mantle Cell Lymphoma? What test detects it?

Answer 21

Translocation (11;14)(q13q32)

(IgH: CyclinD1)

Overexpression of Cyclin D1 pushes cell through the cell cycle.

DETECTED BY FISH

Question 22

Which is more aggressive? CLL/SLL or MCL?

Answer 22

MCL - rapid proliferation

Question 23

What stain indicated a high mitotic rate?

Answer 23

Ki-67 immunostain

Can be used to detect Mantle Cell Lymphoma

Question 24

An elderly patient comes in and has increased total protein and Rouleaux on the peripheral smear. What type of cancer do they have?

Answer 24

Plasma cell neoplasm

Question 25

Where are plasma cell neoplasms primarily located?

Answer 25

Mostly in the bone marrow. (MYELOMA)

Question 26

What is a Rouleaux?

Answer 26

Poker chip stacks of RBCs on peripheral smear.

Question 27

What will the bone marrow of a person with a plasma cell neoplasm look like?

Answer 27

Tons of plasma cells everywhere.

Question 28

Immunophenotype of a plasma cell neoplasm.

Answer 28

``` CD38+++ CD138+++ CD19- CD20- light chain restricted ```

Question 29

What is the disease course of a plasma cell lymphoma?

Answer 29

MGUS - Monoclonal gammopathy of uncertain significance 1% of people per year transition to MULTIPLE MYELOMA.

Question 30

What's the mnemonic for plasma cell neoplasms?

Answer 30

Rouleaux formation on peripheral smear looks like poker chips. The more poker chips you have, the More Money you have. Multiple Myeloma.

Question 31

What is the difference between MGUS *monoclonal gammopathy of uncertain significance* and multiple myeloma?

Answer 31

MGUS is mild, and a precursor to Multiple Myeloma, the clinically active form of plasma cell neoplasms.

Question 32

What is the messed up cell type in Follicular B-Cell lymphoma?

Answer 32

Can be centrocytes or centroblasts. (the more Centroblasts involved, the more aggressive the disease) Goes with the general rule: The more differentiated a cell population is, the less aggressive the cancer.

Question 33

What is the pathophisiology associated with Follicular B-cell lymphoma?

Answer 33

Normally, germinal center B cells have a 99% apoptosis rate. In Follicular Lymphoma, the B-cells over express Bcl-2, an anti-apoptotic protein, therefore CAN"T UNDERGO APOPTOSIS.

Question 34

How does the over expression of Bcl-2 in Follicular B-cell Lymphomas occur?

Answer 34

A centroblast translocates Bcl-2 to an IgH promotor region.

Question 35

What does the lymph node histology look like in Follicular B-Cell Lymphoma?

Answer 35

Tons of follicles, lymph node enlargement, and the germinal center (follicles) lack Tingible Body Macrophages. Lack of mitotic figures.

Question 36

What immunostain do you do if you suspect follicular B-cell Lymphoma?

Answer 36

Bcl-2 immunostain Normal follicles will not stain because their B-cells don't express Bcl-2. Cancerous ones will stain. Google it.

Question 37

Immunophenotype of Follicular B-cell Lymphoma.

Answer 37

``` CD19+ CD20+ CD10+ Bcl-2+ Bcl-6+ ```

Question 38

What is the translocation of Follicular B-cell Lymphoma? (in genetic form)

Answer 38

t(14;18)(q32;q21)

Question 39

Where is the Bcl-2 gene located on the genome?

Answer 39

18q21

Question 40

What cancer can Follicular B-Cell Lymphoma transform into?

Answer 40

Diffuse Large B-cell Lymphoma | 30% of cases

Question 41

What is the grade of Follicular B-Cell Lymphoma based on? How is prognosis related to grade, in this case?

Answer 41

The cells present. Grade 1 - lots of CentroCYTES Grade 2 - Centrocytes/blasts Grade 3 - Centroblasts (aggressive) Prognosis worsens with increasing grade.

Question 42

You see Reid/Sternberg cells on a peripheral smear. Describe the cells. What does the patient have?

Answer 42

The cells have "owl eyes" - blinucleate mirror images. There is NO Ig expression on the cells. Patient has classical Hodgkins Lymphoma

Question 43

What does a lymph node with Hodkins Lymphoma look like?

Answer 43

Depends on the type. Google it. Nodular sclerosing (worse prognosis) and Lymphocute rich HL (best prognosis)

Question 44

Immunophenotype of Hodkins Lymphoma.

Answer 44

2 owl eyes x15 = 30 CD15+ CD30+ Pax5+ Pax5+ is a B-cell transcription factor.

Question 45

YOU CAN'T TEST FOR HODGKINS LYMPHOMA WITH FLOW CYTOMETRY. Why?

Answer 45

The Reed-Sternberg cells are large and fragile, and don't survive when the lymph node is diced up and prepped.

Question 46

What form of Hodgkins lymphoma has cells that DO express Ig and normal B-cell markers?

Answer 46

Nodular Lymphocyte Predominant Hodgkins Lymphoma (NLPHD)

Question 47

How can you tell the difference (histologically) between Classical and Nodular Lymphocyte Predominant Hodgkins Lymphomas?

Answer 47

Classical has Reed-Sternberg cells. Nodular Lymphocyte Predominate form has POPCORN CELLS with surface Igs and normal B-cell markers.

Question 48

What is the immunophenotype of Nodular Lymphocyte Predominate Hodgkins Lymphoma? (NLPHD)

Answer 48

CD15+ CD30+ Pax5+ (B-cell TF) CD20+ NORMAL B-CELL MARKERS