Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) involves extra nodal tissue and shows infiltration of the marginal zones and inter follicular regions.
- Gastric MALT is associated with H. pylori infection in up to 90% of cases.
- MALT in the thyroid has been associated with Hashimoto’s thyroiditis (~20% of cases).
- Ocular MALT lymphomas have been associated with various infections.
Immunophenotype
Marker
|
Comment
|
Negative
|
|
Positive
|
|
Positive
|
|
Positive
|
|
Negative
|
|
Negative
|
|
Negative
|
|
30-50% may be positive (not significant in the terminal ileum)
|
|
Positive
|
|
Negative
|
|
Highlights disrupted networks of FDCs.
|
|
Low
|
|
Negative
|
|
Highlight plasma cell component, which may be studied with kappa/lambda markers to prove monoclonality.
|
References
Parker, A., et. al. “Best Practice in Lymphoma Diagnosis and Reporting.” British Committee for Standards in Haematology, Royal College of Pathologists. April, 2010.