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The gene encoding the beta-chain of the T-cell antigen receptor (TCR) has been analyzed for evidence of rearrangement in skin, blood, and lymph node specimens from 23 cases of known or suspected cutaneous T-cell lymphoma (CTCL). Two cutaneous large cell lymphomas, 4 cases of Sézary syndrome, and 5 cases of advanced (tumor) stages of mycosis fungoides showed clonal rearrangement of the TCR beta-chain gene in all samples, including lymph nodes in which histologic examination revealed only dermatopathic lymphadenitis. These results indicate that DNA analysis provides a valuable means for improving the diagnosis of extracutaneous disease in advanced stages of CTCL. In contrast, the gene was in a germline configuration in all samples from 12 patients with plaque stages of mycosis fungoides or suspected early CTCL, suggesting that in these 2 conditions the T-cell proliferation is either polyclonal or contains very few monoclonal (i.e., neoplastic) cells. [ABSTRACT FROM AUTHOR]

Lymphomatoid papulosis (LyP) is characterized by the presence of large multinucleated cells resembling Reed- Sternberg (RS) cells. Evidence of antigenic similarity between these two cell types has been sought by immunohistologic labeling of 10 biopsies from cases of LyP with monoclonal antibodies against Ki-I and other RS and Hodgkin (H) cell-associated antigens. In all cases studied, a proportion of the large atypical cells expressed the Ki-1 antigen. On the contrary, in 20 biopsies of benign skin lesions or cutaneous T-cell lymphomas, Ki-1-positive cells were absent or only occasionally present. Furthermore the large atypical cells of LyP also expressed antigens (e.g., T3, T4, HLA-DR, IL-2 receptors) which we have previously demonstrated on RS cells in the majority of cases of Hodgkin's disease (HD). These findings, in conjunction with the observation that Ki-1 antigen expression can be induced on peripheral blood lymphocytes following exposure to phytohemagglutinin or HTLV 1, provide evidence that the Ki-1 positive cells in LyP represent activated T cells as RS cells do in many cases of HD. [ABSTRACT FROM AUTHOR]