Small B Cell NHLs

Question 1

what are small B cell NHLs derived from?

Answer 1

mature B cells

Question 2

is bone marrow involvement common in small B cell NHLs?

Answer 2

yes. lots of stage 4 disease (as well as liver/spleen involvement)

Question 3

immunophenotypic profile for follicular lymphoma

Answer 3

CD19/20+ (mature B cell)
CD5- (not T cell)
kappa/lambda restricted
CD10+, BCL6+, BCL2+ (germinal center origin, but cells don’t apoptose)

Question 4

immunophenotypic profile for CLL/SLL

Answer 4

CD19/20+ (mature B cell)
CD5+ (aberrant T cell marker)
kappa/lambda restricted
CD10-, BCL6-, BCL2+ (not from germinal center)

Question 5

immunophenotypic profile for marginal zone lymphoma (MALT)

Answer 5

CD19/20+ (mature B cell)
CD5- (not T cell)
light chain restriction
CD10-, BCL6-, BCL2+ (not germinal center origin)
** no distinct immunophenotypic marker***

Question 6

what is the most common NHL?

Answer 6

follicular lymphoma

Question 7

what age group does follicular lymphoma affect?

Answer 7

middle age and older

Question 8

morphology of follicular lymphoma

Answer 8

nodular neoplasm within lymph node. loss of mantle, polarity, tingible macrophages. complete loss of normal features. Contains centroblast & centrocytes.

Question 9

growth of follicular lymphoma

Answer 9

indolent

Question 10

clinical manifestation of follicular lymphoma

Answer 10

generalized lymphadenopathy, typically caught at stage 4 (disseminated) due to slow growth. spleen/liver involvement common with miliary lesions and painless splenomegaly. extra nodal involvement is uncommon.

Question 11

prognosis of follicular lymphoma

Answer 11

incurable due to indolent growth (therapies target cell division). 7-9 year survival

Question 12

current therapy for follicular lymphoma

Answer 12

observation, symptomatic relief, Rituxan, multiagent regiments (CHOP)

Question 13

more severe follicular lymphoma

Answer 13

can transform into diffuse large b cell lymphoma. can occur after treatment and cuts survival to <1yr

Question 14

derivation of follicular lymphoma

Answer 14

germinal center B cell

Question 15

centrocytes

Answer 15

small cleaved, low grade germinal center b cells that can disseminate through the blood

Question 16

centroblasts

Answer 16

large, transformed noncleaved germinal center B cells.

Question 17

how to grade follicular lymphomas

Answer 17

1. Cytology: centroblast count
2. Extent of nodularity

(higher grades=higher centroblasts, diffuse nodules=more aggressive)

Question 18

bone marrow pattern in stage 4 follicular lymphoma

Answer 18

paratrabecular aggregates

Question 19

follicular lymphoma translocation

Answer 19

t(14;18). IgH-Bcl2=constitutive Bcl2 activity=no apoptosis

Question 20

Ki67 in follicular lymphoma

Answer 20

low. cells aren’t proliferating because they aren’t dying. Just accumulate instead.

Question 21

CLL/SLL derivation

Answer 21

unclear. either 1. mature B cells that just left marrow, haven’t encountered antigen, no TdT/CD34, with light chains or 2. B cells that encountered antigen in follicle and are chilling in the margin

Question 22

CLL/SLL stands for…

Answer 22

Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (circulating cells and solid masses)

Question 23

epidemiology of CLL/SLL

Answer 23

affects 60+ and males more than females. most common adult leukemia

Question 24

clinical features of CLL/SLL

Answer 24

usually asymptomatic, generalized lymphadenopathy, always stage 4, spleen&liver involvement, peripheral blood involvement (unlike FL), immune dysregulation (AIHA or thrombocytopenia) caused by normal B cells

Question 25

CLL/SLL prognosis

Answer 25

variable survival 4-6 years, easily transforms to prolymphocytic leukemia or undergoes Richter's Transformation (both <1yr survival and resistant to treatment)

Question 26

Richter's Transformation

Answer 26

transformation of CLL/SLL to diffuse large B cell lymphoma

Question 27

CLL/SLL morphology

Answer 27

diffuse sheet of small resting lymphocytes in lymph node with proliferation centers of larger transformed cells with more cytoplasm (pro lymphocytes or paraimmunoblasts). No follicle structure, effacement of architecture

Question 28

peripheral blood smear of CLL/SLL

Answer 28

lymphocytosis, smudge cells (disrupted white cells), spherocytes (autoimmune attack), nucleated RBCs, increased reticulocytes (polychromasia)

Question 29

CLL/SLL bone marrow involvement

Answer 29

nodular aggregates (or diffuse spread) in marrow away from trabecular in area of interstitium

Question 30

naive form of CLL/SLL

Answer 30

contains rearranged but unmutated Ig, pre-germinal center, Zap70+, aggressive form of the disease

Question 31

post germinal center form of CLL/SLL

Answer 31

contains rearranged and somatically hyper mutated Ig genes, has traversed GC. Zap70-, Indolent

Question 32

Marginal Zone Lymphoma origin

Answer 32

comes from ill defined area outside germinal center where B cells go after encountering antigen and either become memory or plasma B cells.

Question 33

three separate marginal zone lymphoma diseases

Answer 33

Nodal, Muscosal/Extranodal (MALT), Splenic

Question 34

MALT stands for...

Answer 34

extranodal marginal zone lymphoma of mucosa associated lymphoid tissue

Question 35

Cause of MALT

Answer 35

chronic inflammatory lesions (helicobacter, campylobacter, ect)

Question 36

MALT prognosis

Answer 36

indolent, but still can transform to diffuse large B cell lymphoma

Question 37

sites of MALT

Answer 37

Stomach, Small bowel, skin, orbit, Lung, Parotid, thryoid

Question 38

MALT morphology

Answer 38

abnormal germinal centers with expanded margins, and effacement of underlying architecture. small mature lymphocytes beyond margin, monocytoid b cells in margin, ample plasma cells

Question 39

consequence of increased plasma cells in MALT

Answer 39

can secrete a low level of Ig into serum and urine (paraprotein)

Question 40

main mechanism of MALT lymphomas

Answer 40

inhibit apoptosis/promote cell growth via NF-kB activation

Question 41

treatment of MALT

Answer 41

can treat underlying infections up to a certain point and neoplasm will regress. eventually cellular change will be independent of inflammatory stimulus and chemotherapy is required