Detection of a t(4;14)(p16;q32) in two cases of lymphoma showing both the immunophenotype of chronic lymphocytic leukemia

Reciprocal IGH/14q32 translocations are detectable in 55-70% of patients with plasma cell myeloma; e.g., the adverse t(4;14)(p16;q32) fusing the IGH and FGFR3 genes (immunoglobulin heavy chain/fibroblast growth factor receptor 3). In a minority of patients with B-lineage chronic lymphocytic leukemia (CLL), reciprocal IGH/14q32 translocations have been reported as well. We describe the occurrence of a t(4;14)(p16;q32) in two lymphoma patients showing the immunophenotype of B-CLL, which, to our knowledge, is the first report on such an association. The first patient, a 72-year-old female, showed mature lymphocyte infiltration of the bone marrow and marked splenomegaly. Immunophenotyping revealed aberrant CD5 expression and light-chain lambda restriction on mature B-lymphocytes corresponding to a B-CLL. Interphase fluorescence in situ hybridization (FISH) plus chromosome banding revealed a t(4;14)(p16;q32) in addition to an unbalanced der(16)t(8;16)(q23;p13) and a del(8)(p11). The second patient, a male of 65 years, showed marked peripheral leukocytosis. Immunophenotyping revealed the phenotype of CLL/PLL (chronic lymphocytic leukemia/prolymphocytic leukemia). Again, FISH together with karyotyping revealed a t(4;14)(p16;q32). These two cases with an t(4;14), but the immunophenotype of B-CLL, demonstrate the genetic variability of B-cell lymphomas and the potential of specific metaphase cultivation techniques using oligonucleotides to increase our insights in the genetic pathways of these heterogeneous disorders.