Nodal Marginal Zone B Cell Lymphoma

Definition

B cell neoplasm composed of small and medium sized cells that involves the mantle and marginal zones of peripheral lymph nodes

Biphasic population with mantle and marginal zone distribution
- Small round lymphocytes surround and replace follicles
- Medium sized cells with clear cytoplasm in surrounding marginal zone
  - Scattered large blasts may be intermixed
- Occasional features
  - Plasmacytoid differentiation
  - Epithelioid histiocytes
Marginal zone type lymphocytes may be numerous
- Small cells with clear cytoplasm
Marrow and peripheral blood may be involved
Lacks specific markers of other small cell lymphomas
- Negative to infrequent for CD23, bcl1, CD5, CD10
- Positive for B lineage markers and bcl2
- No specific positive immunologic marker
  - Immunologically, a diagnosis of exclusion
Lacks involvement of extranodal tissues
Transformation to large B cell lymphoma may occur

Yasodha Natkunam MD PhD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342

Original posting:: May 1, 2006