Polymerase chain reaction analysis of T-cell receptor γ gene rearrangements in cutaneous B-cell lymphomas

PCR analyses of T-cell receptor (TCR) gamma gene rearrangements in B-lymphoid neoplasms have shown lineage infidelity and double rearrangements involving both immunoglobulin heavy chain (IgH) and TCR gamma genes. In order to investigate if this event is also a feature of cutaneous B-cell malignancies, we tested for clonal TCR gamma rearrangements a panel of immunophenotypically and genotypically well characterized cutaneous B cell lymphomas (CBCL). Fifteen samples of frozen CBCL biopsies were selected for the study. Diagnoses were established by routine histology and immunohistochemistry. Each of these cases displayed clonal IgH gene rearrangement. Polymerase chain reaction (PCR) analysis of the TCR gamma rearrangements followed by high-resolution polyacrylamide gel electrophoresis was utilized for detection of clonal TCR gamma rearrangements. In our investigation, none of the cases of CBCL investigated by PCR showed the presence of clonal TCR gamma gene rearrangements. These data indicate that double rearrangements involving both IgH and TCR gamma genes are not a feature of CBCL and confirm the B cell lineage specificity of this group of cutaneous lymphoid neoplasms.