Wednesday 2 November 2005
HPC:279 : Lymphoplasmacytic lymphoma in the bone marrow.
Definition: Lymphoplasmacytic lymphoma (LPL) includes most cases of Waldenstrom macroglobulinemia and consists of a diffuse proliferation of small lymphocytes, plasmacytoid lymphocytes and plasma cells.
The typical histologic features of small lymphocytic lymphoma, mantle cell lymphoma and marginal zone lymphoma must be absent.
The cells express surface and cytoplasmic IgM and are IgD-.
CD10 is negative, whereas a proportion of cases have faint CD25 and CD11c expression.
The postulated normal counterpart is a B-lymphocyte differentiating into an IgM-secreting plasma cell.
The putative cell of origin is a peripheral B-lymphocyte transforming into plasma cell with mutated IgV genes and ongoing mutations.
t(9;14)(p13;q32) (PAX5/IGH) (50% of cases) (9p13 and 14q32)
- The t(9;14)(p13;q32), fusing the IgH gene with the BSAP (B-cell specific activator protein), also called PAX5, has been found in 50% of the cases.
- This balanced translocation cannot be viewed as specific for this lymphoma, having been reported in rare marginal zone lymphomas and large cell lymphomas.
other 14q32 translocations
- with 8q24 ( t(8;14)(q24;q32))
- 18q21 ( t(14;18)(q32;q21)
trisomies of chromosomes 3 (+3; trisomy 3) and 12 (+12; trisomy 12) and an isochromosome 6p (i(6p))
Cuneo A and Castoldi GL . Lymphoplasmacytic lymphoma. Atlas Genet Cytogenet Oncol Haematol. May 2000 . URL : http://AtlasGeneticsOncology.org/Anomalies/LPLID2074.html
t(9;14)(p13;q32) denotes a subset of low-grade non-Hodgkin’s lymphoma with plasmacytoid differentiation. Offit K, Parsa NZ, Filippa D, Jhanwar SC, Chaganti RS. Blood. 1992 ; 80 (10) : 2594-2599. PMID 1384792
A revised European-American classification of lymphoid neoplasms: a proposal from the International Lymphoma Study Group. Harris NL, Jaffe ES, Stein H, Banks PM, Chan JK, Cleary ML, Delsol G, De Wolf-Peeters C, Falini B, Gatter KC. Blood. 1994 ; 84 (5) : 1361-1392. PMID 8068936
Genetics of small lymphocyte disorders. Panayiotidis P, Kotsi P. Seminars in hematology. 1999 ; 36 (2) : 171-177. PMID 10319386