Extranodal Marginal Zone B Cell Lymphoma

Supplemental Studies

B lineage 100%
Immunoglobulin light and heavy chains variably detectable
- More frequent in plasmacytoid cases
CD23 8%
CD5 negative
CD43 35%
bcl1 negative
CD10 2%
bcl2 65-90%
bcl6 negative
Cases with transformation to diffuse large cell lymphoma maintain CD5 and CD10 negativity
CD138 can be extensive if plasmacytoid differentiation is prominent
bcl10 nuclear overexpression reported in cases with specific translocations
- We do not find this stain reliable at this time
- If present this would be an indication of resistance to antibiotic therapy
Immunoproliferative small intestinal disease variant
- Alpha heavy chain positive
- No light chain

t(11;18)(q21;q21)
- 40% of gastric and lung cases
  - Less frequent in salivary and orbital cases
- Low likelihood of large cell transformation
- Not responsive to antibiotic therapy
- PCR is currently the best test for this
  - FISH is not reliable
t(1;14)(p22;q32)
- 5% of gastric and lung cases
- Not responsive to antibiotic therapy
- Low likelihood of large cell transformation
Trisomy 3
- 60% of cases