We propose that FL is a malignancy of cells that acquire both translocation t(14;18) and self-BCR, inducing them to proliferate and mature, resistant to negative selection.
Polymerase chain reaction for t(14;18) using primers to the major breakpoint cluster region was performed on 14 cases of ENFL and the incidence of the translocation compared with that found in 16 cases of stage 1 nodal FL.
These results support the concept of a subtype of follicular lymphoma lacking t(14;18) involving the major breakpoint cluster region, and with a propensity to arise in the skin.
Molecular analysis showed that BCL2 was rearranged in the major breakpoint cluster region and had joined into the immunoglobulin heavy chain gene as in follicular lymphoma.
In this patient's leukemic cells, the breakpoint of the t(14;18) translocation occurred in the major breakpoint-cluster region of the BCL2 gene and became linked to the JH4 joining-region gene segment of the immunoglobulin heavy-chain locus on the 14q+ chromosome as previously observed in follicular lymphoma.
Nucleotide sequence of a t(14;18) chromosomal breakpoint in follicular lymphoma and demonstration of a breakpoint-cluster region near a transcriptionally active locus on chromosome 18.