Nodal Marginal Zone Lymphoma Flashcards

1
Q

What is the definition of Nodal Marginal Zone Lymphoma ?

A
  • primary nodal B cell neoplasm
  • morphologically it resembles lympho nodes involved by marginal zone lymphoma of extranodal sites or the spleen
    • BUT there can be no evidence of extranodal disease
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2
Q

What is the epidemiology of Nodal Marginal

Zone Lymphoma ?

A
  • rare lymphoma (1.5-1.8%)
  • usually seen in people ~60 years of age
  • M = F ratio

IMP: this lymphoma can be seen in kids, but it is then classified as Pediatric Nodal Marginal Zone Lymphoma

IMP: there has been a noted increased incidence in women with autoimmune disorders.

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3
Q

What are the sites of involvement of

Nodal Marginal Zone Lymphoma?

A
  • peripheral lymph nodes
  • sometimes can also involve the bone marrow and peripheral blood

IMP: cannot have evidence of extranodal disease, otherwise is most likely lymph node involvement by an extranodal MALT lymphoma.

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4
Q

What are the clinical features of Nodal

Marginal Zone Lymphoma ?

A
  • usually patients are asymptomatic and present with localized or generalized peripheral lymphadenopathy
    • head and neck lymph nodes are most frequently involved
  • B symptoms are present in up to 20% of patients
  • exclude an extranodal MALT
    • MALT associated with Hashimoto or Sjogrens often disseminates to the lymph nodes
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5
Q

What are the microscopic findings for a

Nodal Marginal Zone Lymphoma ?

A
  • small lymphocytes that surround reactive follicles and expand into the interfollicular zones
  • follicular colonization can be seen
  • IF there is a diffuse pattern, residual follicles can be highlighted by IHC
  • Variable infiltrate of marginal zone B lymphocytes (centrocyte like), scattered plasma cells and transformed B cells (immunoblasts/centroblasts)
    • IMP: cases with predominantly monocytoid B cells are uncommon
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6
Q

What is the differential diagnosis when there

is extensive plasmacytic differentiation of the

nodal marginal zone lymphoma ?

A
  • Lymphoplasmacytic lymphoma
  • Nodal plasmacytoma

IMP: the presence of remnants of FDC meshworks favors NMZL because it likely represents colonization of the follicles.

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7
Q

What does the presence of increased large

cells mean?

A
  • Does not mean anything necessarily, may have >20% large cells but they should still be scattered amongst the other cells
  • They may be more common in the colonized germinal centers

IMP: a composite marginal zone lymphoma and Hodgkin lymphoma have been reported.

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8
Q

What is the pattern of bone marrow involvement ?

A
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9
Q

What is the immunophenotype of Nodal

Marginal Zone Lymphoma ?

A
  • pan B cell markers
  • CD43 co-expression in 20-75% of cases
  • CD23 is usually negative
    • but it can be expressed in as many as 30% of cases
  • CD5 may be seen in up to 20% of cases
    • tend to have more disseminated disease if positive but it does not affect their prognosis
  • Bcl2 positive in most cases
  • Cyclin D1
    • Negative
  • Germinal center markers (CD10, Bcl6, HGAL, and LMO2)
    • Negative but rare reports of positivity
    • IMP: co-expression of more than one GC marker in the interfollicular areas favors a Follicular lymphoma
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10
Q

How can IgD IHC help differentiate nodal MZL

from other lymphomas?

A
  • IgD is usually negative in nodal MZL
  • IgD is positive in other lymphomas that can mimic MZL immunophenotypically
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11
Q

How can MNDA and IRTA1 IHC

help differentiate follicular lymphoma from

nodal Marginal zone lymphoma ?

A
  • MNDA and IRTA1 are positive in 75% of cases of nodal marginal zone but are usually negative in follicular lymphoma
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12
Q

What is the normal postulated counterpart

of nodal marginal zone lymphoma ?

A
  • post-germinal centre marginal zone B cell
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13
Q

What immunoglobulin genes are frequent clonally

rearranged in nodal MZL ?

A
  • predominance of mutated IGHV3 and IGHV4 family members
    • IGHV4-34 are the most common
  • In cases that are associated with hepatitis C virus infection, IGHV1-69 are clonally rearranged
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14
Q

What similar chromosomal abnormalities does

nodal MZL share with splenic and extranodal MZL ?

A
  • Gains of chromosomes 3 and 18
  • Loss of 6q23-24

IMP: no deletions of 7q31 or any recurrent translocations are noted.

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15
Q

What has gene expression profiling identified in

nodal MZL ?

A
  • increased expression of NF-kappaB related genes
  • MYD88 L265P mutation is usually absent but can occasionally be detected.
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16
Q

What is the overall survival rate with nodal MZL

and the prognostic factors?

A
  • 5 year overall survival is about 60-70%
  • Worse prognosis seen with:
    • advanced patient age
    • B symptoms
    • advanced disease stage
  • IMP: proportion of large cells or clustered large cells has no prognostic meaning but MZL can transform to diffuse large B cell lymphoma, so must evaluate for that.
17
Q

What is the definition of pediatric nodal

marginal zone lymphoma ?

A

IMP: very distinct clinical and morphologic characteristics

  • predominantly in males (20:1 ratio)
  • asymptomatic or localized disease in the head and neck areas
18
Q

What is the histology of pediatric nodal

marginal zone lymphoma ?

A
  • similar to adult nodal MZL except that they have large follicles with extension of mantle zone B cells into the germinal centres
    • looks like progressive transformation of germinal centres
19
Q

What are the IHC findings of pediatric

nodal marginal zone lymphoma ?

A
  • light chain can be demonstrated by IHC or flow cytometry
  • similar immunophentype to the adult MZL
  • Bcl2 is positive in 1/2 the cases
  • CD10 is negative
  • IgD can help dilineate an irregular and expanded mantle zone

CD279/PD1

  • shows numerous positive cells in the germinal centres which helps differentiate from pediatric follicular lymphoma
    • less numerous in that entity and pushed to the periphery of those GC
20
Q

What are the molecular findings in pediatric nodal

marginal zone lymphoma ?

A
  • clonal rearrangements of IGHV are detected in almost all cases
  • Trisomy 18 (1/5 of cases) and occasionally Trisomy 3 are identified
21
Q

What is the prognosis for pediatric nodal

marginal zone lymphoma ?

A
  • excellent prognosis
  • very low relapse rate and good long term survival with conservative therapy.
22
Q

What are the key differential diagnoses for

pediatric nodal marginal zone lymphoma?

A
  • Atypical marginal zone hyperplasia with monotypic immunoglobulin expression
    • large cells here also express CD43
    • has been reported in extranodal sites and lymph nodes
    • recommended to do genetic studies to rule out pediatric nodal MZL
  • Marginal zone hyperplasia associated with Haemophilus influenzae
    • marginal zone B cells in this case are IgD positive