262 - Lymphoid Histology & B Cell Lymphoma

Question 1

What is going on in each part of the lymph node follicle?

• Mantle zone:
• Germinal center:
• Cortex:

Answer 1

• Mantle zone: Naive lymphocytes meet antigens
• Germinal center: Proliferating cells differentiate into antigen-specific cells
• Cortex: B cells home here

Question 2

Which area of the lymph node has the most T cells?

Answer 2

Paracortex

Question 3

Describe the Ann-Arbor staging system for lymphoma

Answer 3

• I - single LN region or extranodal site
• II - 2+ LN regions (or 1 extra nodal site and 1+ LN region
  
  • Same side of the diaphragm
• III - LN regions (or extanodal sites) on both side of the diaphragm
• IV - Any of the above with additional extranodal site OR 2+ extra nodal sites with lymph nodes

A if no symptoms, B if symptoms are present

Question 4

Which translocation is associated with Burkitt lymphoma?

What is the product?

Answer 4

• t(8;14)
• Increased expression of c-kit
• “Burk-eight” = 8;14 translocation*
• bur-kit = C-kit*

May also involve IGH (chromosome 2) and IGL (chromosome 22)

Associated with EBV

Question 5

In diffuse large B-cell lymphoma, what do MYC and BCL2 rearrangements indicate about prognosis?

Answer 5

Poor prognosis :(

Question 6

Which lymphomas express high levels of BCL2? (4)

How does BCL2 affect the cell?

Answer 6

• Follcular lymphoma t(14;18)
• Diffuse large B cell lymphoma
• CLL/SLL
• Mantle zone lymphoma

BCL2 inhibits apoptosis

Question 7

What is the cell of origin in extranodal marginal zone lymphoma?

Answer 7

• Antigen-stimulated B cells
• most often in tissue inflamed due to chronic inflammation or autoimmune disorder

Question 8

List 4 tumor markers that may be expressed in Burkitt lymphoma

Answer 8

CD20

CD10

BCL6

MYC

Question 9

What translocation (and product) is associated with mantle cell lymphoma?

Answer 9

• t(11;14)
• Cyclin D1 is fused with the IGH promoter
• -> promotes cell progression through G1/S checkpoint
• -> cell growth

This translocation is diagnostic of mantle cell lymphoma

Question 10

What is the most common translocation (and product) in follicular lymphoma?

Answer 10

t(14;18)

BCL2/IgH

Question 11

Describe the presentation of diffuse large B-cell lymphoma

Answer 11

Rapidly enlarging, symptomatic mass in 1 or several sites

• Usually in adults 50+, but can occur in any age*
• Without treatment, DLCBL is aggressive and fatal.*

Question 12

Which lymphoma is associated with Ki67?

Answer 12

Mantle cell lymphoma

Question 13

B lymphocytes home to which region of the lymph node?

Answer 13

Cortex

Question 14

What 2 factors impact the prognosis of B cell lymphoma?

Answer 14

Tumor biology

Stage

Question 15

Which B cell malignancies might express CD5?

Answer 15

Mantle cell lymphoma

CLL/SLL

CD5 is usually a T-cell marker, but can appear in these B-cell malignancies

Question 16

Which part of the lymph node contains plasma cells?

Answer 16

Medulla

Question 17

Which lymphoma has a germinal center origin and a follicular growth pattern?

Answer 17

Follicular lymphoma

Question 18

What markers are indicative of CLL/SLL? (2)

Answer 18

CD5+

CD20+

CD23+

Weird because CD5 is a T-cell marker, but appears in this B-cell leukemia

Question 19

Which lymphoma is most associated with chronic inflammation?

Answer 19

Extranodal marginal zone lymphoma

• indolent lymphoma arises and is sustained by chronic inflammation
• May be associated with H. pylori induced gastritis
• Cell of origin = antigen-stimulated B cells
• Treating the inflammation will treat the neoplasm

Question 20

Which part of the lymph node contains memory B cells?

Answer 20

Marginal zone

Question 21

What is the major difference between chronic lymphocytic leukemia and small lymphocyte lymphoma?

Answer 21

CLL if >5000 neoplastic cells in the peripheral blood

SLL if more confined to tissue

Both can present with large, asymptomatic lymph nodes

Question 22

A patient with a single lymph node containg lymphoma who has a fever and night sweats would be staged as ____ based on the Ann Arbor staging system?

Answer 22

A patient with a single lymph node containg lymphoma who has a fever and night sweats would be staged as 1B based on the Ann Arbor staging system.

Question 23

What is the most common type of non-Hodgkin Lymphoma in the US?

Answer 23

Diffuse large B cell lymphoma

Question 24

Which lymphoma is associated with a “starry sky” pattern?

Answer 24

Burkitt lymphoma

Question 25

What cell markers are associated with non-Hodgkin Lymphoma with a t(14;18) translocation?

Answer 25

CD20+

Other B cell markers (CD19+)

Germinal B markers (CD10+, BCL6+)

This is follicular lymphoma; treat with anti-CD20 antibody and BCR signaling inhibitor

Question 26

How can we use the ratio of kappa:lambda B cells to determine if a population is clonal?

What would a clonal population indicate?

Answer 26

• Kappa:lamba should be about 1:1
  
  • Note: Dr. Gao’s lecutre (264) says ~1:1, and Dr. Wolniak’s lecture (266) says ~2:1
• Large deviations from this ratio indicate the presence of a clonal population
• Clonal population is bad –> implies lymphoma