Analysis of clonal relationship using single-cell polymerase chain reaction in a patient with concomitant mantle cell lymphoma and multiple myeloma.

We report a case of concomitant mantle cell lymphoma (MCL) and multiple myeloma (MM) in which we investigated the possibility of a clonal relationship. A 76-year-old man was diagnosed with MCL [immunoglobulin (Ig)M,D-kappa; stage IVB] and MM (IgG-kappa; stage I). Ig heavy chain (IgH) gene complementarity-determining region 3 in DNA from both the MCL tumor and from single MM cells from bone marrow smears was amplified to investigate whether there was a clonal relationship between MCL and MM. Sequence analysis revealed no clonal relationship between MCL and MM in our patient.