Clonal T cell population in angioimmunoblastic lymphadenopathy and related lesions.

The arrangements of the T cell receptor (TCR) beta genes were studied in lymph node specimens with the histological characteristics of angioimmunoblastic lymphadenopathy with dysproteinemia (AILD), AILD-like T cell lymphoma (AILD-T), T-zone lymphoma, or Lennert's lymphoma. Eight of 11 cases with AILD or AILD-T showed clonal rearrangements of TCR beta genes: all three AILD cases showed clonal rearrangements of TCR beta genes, while five of 8 AILD-T cases exhibited clonal rearrangement patterns. Malignant lymphoma evolved in one AILD case showed the same rearrangement band of TCR beta genes as its primary AILD lesion. The rearrangement of TCR beta genes was also observed in 2 out of 3 cases with T-zone lymphoma and 2 out of 2 cases with Lennert's lymphoma. None of the cases studied, except one AILD-T case, exhibited clonal rearrangements of immunoglobulin heavy chain genes. The results suggested that a significant proportion of AILD, AILD-T, T-zone lymphoma and Lennert's lymphoma cases are malignancies of peripheral T cell origin.