Ki-1+ Cutaneous Lymphoma: Gene Rearrangement Analysis of Tumor Cells in Tissue and Short-term Culture of a Patient

• Cutaneous malignant lymphomas developed in an 80-year-old man without any evidence of leukemic disseminations of lymphoma cells. Immunohistologic staining showed the expression of Leu-3a, Leu-4, Ki-1, Tac, and HLA-DR antigens on tumor cells in tissue and large lymphoid cells in long-term, interleukin 2-containing culture of tumor explants. DNA samples extracted from the skin tumors and cultured lymphoid cells showed a clonal rearrangement of T-cell receptor (TCR) gene Cβ 1 with the molecular size of 9 kilobases. These findings suggested the T-cell origin of Ki-1 + cutaneous lymphoma cells and the occurrence of a clonal proliferation of tumor cells in culture. ( Arch Dermatol 1988;124:405-408)