Chronic lymphocytic leukemia with a FGFR3 translocation: case report and literature review of an uncommon cytogenetic event.

The t(4;14) (p16; q32) with fusion of the IGH (immunoglobulin heavy chain) and FGFR3 (fibroblast growth factor receptor 3) genes are rarely present in patients with chronic lymphocytic leukemia (CLL), with only two previously reported cases. We herein describe a unique case of CLL with the occurrence of a t(4;14) (p16;q32), trisomy 12, and deletion of 11q13-q23 in the same clonal cells. In contrast to myeloma, in which FGFR3 translocations are a common early cytogenetic hit, FGFR3 rearrangement in CLL appears to occur later in the disease course.