A lymphoproliferative disorder of T gamma cells with the phenotype of cytotoxic/suppressor T-cell.

A 25-yr-old Japanese male showed unique T gamma cell proliferation different from cases reported previously. His clinical and hematological features were characterized by persistent high fever and the appearance of large lymphocytes with abundant cytoplasm and azurophilic granules in the peripheral blood (11% of the leukocyte differential count) and the ascitic fluid. These lymphocytes showed the ability to bind the Fc portion of IgG and they beared the antigen of cytotoxic/suppressor T-cell defined by monoclonal antibodies. T-cells from this patient suppressed the immunoglobulin production of normal B-cells by pokeweed mitogen, although a polyclonal hypergammaglobulinemia was observed in the serum. Chromosomal abnormality indicated the malignant nature of the proliferating T gamma cells in this patient. The clinical, hematological, and immunological findings characterized the disease of this patient as a distinct entity among the lymphoproliferative disorders of T-cell origin.