A Comparative Immunohistochemical Study of Adult T Cell Leukemia and Cutaneous T Cell Lymphoma

Abstract

An immunoperoxidase study of 2 cases of adult T cell leukemia (ATL) and 2 cases of mycosis fungoides (MF) was done using monoclonal antibodies. In ATL, many anti‐interleukin‐2 receptor antibody (LeuIL‐2R)‐positive cells were seen in the dermis and occasionally in the epidermis. In contrast, in MF, LeuIL‐2R‐positive cells were much less frequent. LeuIL‐2R‐positive cells in MF may be non‐malignant T cells; not all LeuIL‐2R‐positive cells may be malignant in ATL. These non‐malignant LeuIL‐2R‐positive cells, we suggest, are involved in the interaction between malignant T cells and reactive infiltrating cells. Furthermore, in addition to OKT6‐positive cells, OKM1‐positive cells were seen in the infiltrates in the dermis in both ATL and MF. OKM1‐positive cells also participate in the mechanism of the skin affinity in ATL and cutaneous T cell lymphomas.