Lymphoplasmacytic Lymphoma
Definition
- Neoplasm composed primarily of small round B lymphocytes with prominent plasmacytoid differentiation, lacking defining features of other types of small B cell lymphomas
Alternate/Historical Names
- Gamma heavy chain disease (variant)
- Immunocytoma
- Lymphoplasmacytoid lymphoma
- Small lymphocytic lymphoma with plasmacytoid features
- Waldenstrom macroglobulinemia
Diagnostic Criteria
- Monomorphic lymphoplasmacytoid population with interfollicular, sinusoidal or diffuse pattern
- Residual germinal centers may be atretic or hyperplastic
- Epithelioid histiocytes may be numerous, may form granulomas
- Hemosiderosis frequently associated with autoimmune hemolytic anemia
- Amyloid may be present
- Three clusters of patterns described by Andriko et al.
- Atretic germinal centers, dlated sinuses, hemosiderosis, no histiocytes
- Interfollicular with normal or hyperplastic germinal centers and epithelioid histoctyes
- Complete effacement of architecture with clusters of epithelioid histocytes
- Nuclear features are those of small round lymphocytes
- Similar to cells of primary follicles
- Clumped chromatin with small or inconspicuous nucleoli
- Cytoplasm shows plasmacytoid features
- Amphophilic staining
- Russell bodies (cytoplasmic inclusions)
- Dutcher bodies (intranuclear inclusions)
- Crystals may be seen in lymphocytes or histocytes
- Most cases secrete IgM with resultant hyperviscosity (Waldenstrom hypergammaglobulinemia)
- Variant secreting truncated gamma heavy chain without light chains termed "gamma heavy chain disease"
- Must lack specific features of other small lymphocytic lymphomas:
- Proliferation centers, mantle pattern, marginal zone pattern, follcular pattern
- CD5 (5%), CD10 (3%), bcl1
- CD23 0-30% in immunohistochemistry
- Up to 60% positive by flow, but weak
- Polymorphous type with 10-40% large transformed cells, immunoblasts and small cleaved cells
- No monomorphous sheets of large cells
- Increased mitotic figures (30/10 hpf vs. 4/10 hpf)
- Occasional Reed-Sternberg like cells
- Reported in 25% of cases
- Worse survival than typical cases
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