Large Cell Lymphoma

Scott R. Owens, MD

Key Facts

Terminology

“Large”: Cells with nucleus ≥ macrophage nucleus or > 2x normal lymphocyte nucleus

Etiology/Pathogenesis

Secondary DLBCL arises from preexisting low-grade lymphoma (“progression” or “transformation”)
Some secondary DLBCL may “overgrow” underlying low-grade component, obscuring evidence of transformation
DLBCL arises in settings positive for Epstein-Barr Virus (EBV) more often than cases arising sporadically

Clinical Issues

GI tract most common extranodal site of DLBCL
May be seen in association with underlying MALT lymphoma, suggesting transformation
Blood and bone marrow involvement uncommon at presentation
May be curable with appropriate therapy

Microscopic Pathology

Diffuse replacement of underlying tissue architecture
Discohesive, large cells
3 recognized variants
- Centroblastic is most common variant
- Immunoblastic
- Anaplastic

Diagnostic Checklist

Hematoxylin & eosin shows intestinal diffuse large B-cell lymphoma infiltrating and disrupting the muscularis propria

and extending into the mucosa

Hematoxylin & eosin shows a high-power view of DLBCL. Some cells have 1 prominent nucleolus (immunoblast-like)

, and others have multiple inconspicuous nucleoli (centroblast-like)

TERMINOLOGY

Abbreviations

Synonyms

Definitions

Neoplasm composed of large B lymphocytes diffusely infiltrating tissue
- “Large”: Cells with nucleus ≥ macrophage nucleus or > 2x normal lymphocyte nucleus

ETIOLOGY/PATHOGENESIS

Primary

Secondary

Arises from preexisting low-grade lymphoma (“progression” or “transformation”)
- Mucosa-associated lymphoid tissue (MALT) lymphoma
- Follicular lymphoma (FL)
- Chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL)
Some secondary DLBCL may “overgrow” underlying low-grade component, obscuring evidence of transformation

Immunodeficiency

Significant risk factor
DLBCL arises in settings positive for Epstein-Barr virus (EBV) more often than cases arising sporadically

CLINICAL ISSUES

Epidemiology

Incidence
- 30-40% of all adults with non-Hodgkin lymphoma (NHL)
Age
- Most common in older patients (median 7th decade)
- Also occurs in young patients
Gender
- Affects males slightly more often than females

Site

≥ 40% of cases extranodal at presentation
- GI tract most common extranodal site of DLBCL
- DLBCL most common lymphoma of GI tract
Stomach
- May be seen in association with underlying MALT lymphoma, suggesting transformation
Small &/or large intestine
- May be seen as progression/transformation of follicular lymphoma or MALT lymphoma
Regional lymph nodes
- May be involved by DLBCL &/or underlying lower grade lymphoma