Indolent B-cell lymphoma with t(14;19) investigated from a molecular perspective.

T(14;19) is an unusual but distinct genomic alteration reported in low-grade B-cell lymphomas. This structural rearrangement places BCL3 in juxtaposition with IGH inducing proliferation and has been found in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), marginal zone lymphoma (MZL), and other low-grade B-cell lymphomas. While there are some case series describing this in the context of other cytogenetic alterations, there are limited clinical cases examined from a molecular perspective. We herein describe a case of a low-grade B-cell lymphoma with t(14;19) resulting in IGH::BCL3 fusion on which we performed whole exome sequencing to investigate genetic variants that could contribute to its pathogenesis. We found pathogenic alterations including a variant in CXCR4 which has been shown to be recurrently mutated in different low-grade B-cell lymphomas including lymphoplasmacytic lymphoma (LPL) and MZL. We describe this interesting case in the context of its genomic findings and how it contributes to the literature as a whole.