B cell neoplasms: Marginal zones, Hairy cell, Prolymphocytic leukemia

Question 1

What is the morphology of

Nodal Marginal Zone Lymphoma ?

Answer 1

• Monocytoid B cells
  
  • proliferation of small round lymphocytes with abundant pale cytoplasm and indented nuclei
• clonal plasma cells with dutcher bodies in the background
• Pattern:
  
  • diffuse, sinusoidal, or interfollicular
  • Follicular colonization (permeation) can be seen
  • expansion of marginal zones with residual reactive follicles in background

Question 2

What is the characteristic

translocation associated with

Nodal Marginal Zone Lymphoma ?

Answer 2

• No specific translocation is associated with it

Question 3

MALT lymphomas [extranodal marginal zone]

have what morphology in tissue ?

Answer 3

• variably destructive and/or tumefactive with permeation into epithelial lesions
• clonal plasma cells can be seen
• associated with chronic antigenic stimulation
  
  • typically from infectious agents

Question 4

What is the morphology of

Splenic Marginal Zone Lymphoma ?

Answer 4

• mainly involves the white pulp, but can spill over into the red pulp
• may involve splenic hilar lymph nodes, but should not involve any other lymph nodes in the body
• liver sinusoids can be involved
• peripheral blood
  
  • usually at very low levels

Question 5

What is the morphology of peripheralized

splenic marginal zone lymphocytes ?

Answer 5

• leukemic cells have small nuclei
  
  • abundant pale cytoplasm
  • irregular cytoplasmic borders
  • polar villous projections

Question 6

What are the features that point towards a peripheralized splenic marginal zone lymphoma

vs. HCL ?

Answer 6

• distinct nucleolus (absent in HCL)
• polar villi (usually circumferential in HCL)
• nodular pattern of bone marrow involvement (HCL will be interstitial or diffuse)

Question 7

What malignancy can present with

blood lakes in the spleen and the bone marrow ?

Answer 7

• Hairy cell leukemia
  
  • this is not a common finding in splenic marginal zone lymphoma

Note: in the spleen HCL involves the red pulp diffusely while splenic MZL involves the white pulp

Question 8

What infectious disease has been

associated with splenic marginal zone lymphoma ?

Answer 8

• Hepatitis C infection
  
  • Note: can sometimes be associated with nodal marginal zone as well

Question 9

How can remission be achieved for

splenic marginal zone lymphoma ?

Answer 9

• splenectomy can lead to remission

Question 10

What is the immunophenotype of

ALL the Marginal Zone Lymphomas ?

Answer 10

• Positive:
  
  • CD19, CD20, CD79a
  • FMC7, bcl2
  • sIg –> usually IgM
• Negative:
  
  • CD5, CD23, CD10, CD103
  • Annexin A1, and CD11c
• CD43 (+) in 50% of cases
• plasma cells contain monoclonal cytoplasmic light chains

Note: review table of antigenic stimuli p. 229

Question 11

MALT lymphoma with t(11;18)

is found where ? what are the genes?

Answer 11

• stomach and lung
• rearrangement of:
  
  • API2 and MALT1

Question 12

MALT lymphoma with t(14;18)

is found where ? what are the genes?

Answer 12

• ocular, parotid, and cutaneous sites
• fusion of genes:
  
  • MALT1-IGH

Question 13

MALT lymphoma with t(3;14)

is found where ? what are the genes?

Answer 13

• ocular, thyroid and cutaneous sites
• genes associated:
  
  • FOXP1-MALT1

Question 14

.

MALT lymphoma with t(1;14)

is found where ? what are the genes?

Answer 14

• seen in lung and small bowel

Note: +3 and +18 are seen nonspecifically in all sites