Thus, 17 cases of lymph node-based LPL were studied with fluorescence immunophenotypic and interphase cytogenetics for the investigation of neoplasia (FICTION) using a CD79a antibody and probes to detect trisomies of chromosomes 3 (15 cases), 12 (16 cases), and 18 (17 cases); rearrangements (R) of IgH (10 cases), BCL6 (6 cases), PAX5 (7 cases), and MALT1 (16 cases); and deletion 6q21 (7 cases).
In contrast to initial observations describing this translocation in lymphoplasmacytic lymphoma (LPL) and LPL-derived large B-cell lymphoma, our data showed a wide morphologic and clinical spectrum associated with the PAX5/IGH rearrangement, pointing to an association between this aberration and a subset of de novo DLBCLs presenting with advanced disease and adverse prognosis.
This study also confirms recent reports that found an absence of PAX5 rearrangements in LPL, suggesting the reassessment of PAX5 rearrangements in LPL.
Thus, an understanding of the PAX-5 gene's physiological role in B-cell development and the pathological role in tumorigenesis may lead to the optimal clinical treatment strategy for LPL and LPL-derived diffuse large cell lymphoma (DLCL).
t(9;14)(p13;q32), a subtype of 14q32 translocation, plays an essential role in the development of lymphoplasmacytoid lymphoma. t(9;14)(p13;q32) Causes juxtaposition of the PAX-5 gene on 9p13 and the IgH gene on 14q32, leading to the deregulation of the PAX-5 gene.
The t(9;14) translocation associated with the B cell tumor lymphoplasmacytoid lymphoma juxtaposes the PAX5 gene into the vicinity of the IGH locus to deregulate PAX5 expression.
These findings suggest that the PAX-5 gene is the target of the t(9;14) in LPL whereby its expression may be deregulated by juxtaposition to IgH regulatory elements, thus contributing to lymphomagenesis.