T-lymphocyte subsets in follicular lymphomas compared with those in non-neoplastic lymph nodes and tonsils

Using monoclonal antibodies on frozen sections, the authors define the anatomic localization of T-lymphocyte subsets in follicular lymphomas as well as in nonneoplastic lymph nodes and tonsils. The percentage of Leu-1+ T cells in the follicles of follicular lymphomas (20 per cent) was virtually identical to that seen in the follicles of nonneoplastic lymph nodes or tonsils (22 per cent). There were 50 per cent T cells in the interfollicular regions of follicular lymphomas and 75 per cent in the paracortical regions of the nonneoplastic specimens. In neoplastic follicles the number of Leu-3a+ cells was 67 per cent of the number of Leu-1+ cells, whereas, virtually the entire T-cell population in the nonneoplastic follicles expressed the Leu-3a antigen. These T cells of helper phenotype may facilitate the neoplastic process or an immune response against it or may be bystanders to the B-cell proliferation. Hum Pathol 13:618-625, 1982