T-cell receptor and B-cell immunoglobulin heavy chain (IgH) or light chain (Igk) gene rearrangement studies can be supportive of a lymphoma diagnosis with identification of monoclonality in a morphologically suspicious lymphoid infiltrate.
Molecular immunoglobulin kappa (Igk) light chain testing is a useful complement to B-cell heavy chain (IgH) gene rearrangement analysis. Igk gene rearrangement can provide confirmation of clonality in post-germinal center (mature) neoplasms where clonotypic IgH signatures may not be detected due to somatic hypermutation of VH genes. The Igk assay, in addition to identifying clonality in atypical lymphoproliferative disorders, can also support a differential diagnosis between reactive lesions and hematologic malignancies, and assign presumptive lineage in mature monoclonal lymphoproliferative disorders.