Comparative study of cutaneous T-cell lymphoma and adult T-cell leukemia/lymphoma

An important disease entity distinct from cutaneous T-cell lymphoma (CTCL) in Japan is adult T-cell leukemia/lymphoma (ATL), which shows almost the same phenotype as CTCL, ie, a helper/inducer T-cell phenotype (CD4-positive, CD8-negative), and usually involves the skin. This article describes differences between CTCL and ATL in terms of clinical and immunopathologic cell surface features. In patients with ATL, the predominant physical findings were lymph node, bone marrow and skin involvement, hepatosplenomegaly, leukemic manifestations, and an aggressive course. In patients with CTCL, in contrast, only skin lesions predominated at the onset of the disease and a relatively good prognosis was shown. The predominant phenotype of the neoplastic cells in the skin of patients with CTCL was CD3+, CD4+, CD29+, CD45RO+, HLA-DR+, HLA-DQ+, CD7-, L-selectin-, and CD45RA-. Some phenotypic discrepancy was found between the neoplastic cells in the peripheral blood, lymph nodes and skin of patients with ATL with respect to CD45RA and CD45RO, and CD7, CD29, CD25, and HLA-DR. That is, the predominant neoplastic cell phenotype was helper T-cell, which was CD3+, CD4+, L-selectin+, CD25+, CD45RA+, HLA-DR+, CD29-, and CD45RO- in peripheral blood, and CD3+, CD4+, L-selectin+, CD29+, CD45RO+, HLA-DR+, and CD45RA- in the skin and lymph nodes. Phenotypic heterogeneity of ATL cells and heterogeneity of CD45R isoform expression on ATL cells were evident in different organs. These findings confirm that the difference in antigen expression on the cell surface might reflect the clinical features of ATL and CTCL. CTCL cells do not share the same phenotype as ATL cells.