T cell subset heterogeneity in a series of patients with mycosis fungoides and Sézary syndrome.

The diagnostic value of the identification of T cell subsets in skin biopsies from a series of eight patients (clinical stages I-IV) with cutaneous T cell lymphoma (6 with mycosis fungoides and 2 with Sézary syndrome) was determined with an indirect immunoperoxidase technic using commercially available monoclonal anti-T lymphocyte antibodies. Each patient had a mixture of helper and suppressor T cells within both the dermis and the epidermis, although helper T cells predominated approximately 2:1 over suppressor cells in all except two patients. This pattern is not appreciably different from that reported in benign inflammatory dermatoses. One patient with Sézary syndrome who had had an unusually protracted course was found to have a greater number of suppressor cells than helper cells within the epidermis. We conclude that the in situ identification of T cell subsets adds little, if any, diagnostic sensitivity to standard histopathologic methods in cutaneous T cell lymphoma.