[A patient with adult T cell leukemia in smoldering stage expressing an aberrant phenotype of CD3- and CD4+].

This report is of a patient with adult T cell leukemia (ATL) in the smoldering stage showing expression an aberrant phenotype of CD3-, CD4+ and CD8-. A 71-year-old woman was admitted to our hospital in December 1992, because of skin eruption and persistent low grade fever. Laboratory examination showed a leukocyte count of 7,000/microliter with 29% abnormal lymphocytes. The diagnosis of ATL was made by the detection of serum anti-HTLV-I antibody and the monoclonal integration of HTLV-I proviral DNA in abnormal lymphocytes. ATL cells at diagnosis were CD3+, CD4+ and CD8+. However, one month later ATL cells lacked CD3 and CD8. Three color analysis showed that most of the CD25+ cells were CD3- and CD4+.