We present an extensive characterization of 10 B‐cell lymphomas with a t(9;14)(p13;q32). The presence of the PAX5/IGH gene rearrangement was demonstrated by fluorescence in situ hybridization (FISH) using a validated probe set, whereas complex karyotypic changes were reassessed by multiplex‐FISH (M‐FISH). Pathologic and clinical review revealed the presence of this rearrangement in 4 histiocyte‐rich, T‐cell‐rich B‐cell lymphomas (HRTR‐BCLs) and 2 posttransplantation diffuse large B‐cell lymphomas (PTLD‐DLBCLs). 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. In addition, the recurrent incidence of this rearrangement in both HRTR‐BCL (4 cases) and PTLD‐DLBCL (2 cases) was previously unrecognized and is intriguing. © 2005 Wiley‐Liss, Inc.