Erythrophagocytic OKT4+ lymphocytes with suppressor activity in Sezary syndrome

We report a rather peculiar case of cutaneous T cell lymphoma with pathological features simulating malignant histiocytosis. The patient suffered 7 years previously from cutaneous T cell lymphoma (mycosis fungoides). The disease involved the skin and lymph nodes. In 1986 the clinical picture was compatible with Sezary syndrome. Ninety-nine percent of her peripheral blood lymphocytes were OKT11+ (T cells) OKT4+, (T helper cells), OKT6-, (thymocyte), OKT10-, (Stem cells), Sig-, (B cells), 70 of them SRBC+. Thirty percent were positive for mouse red blood cells (Rosette+). The ratio of helper/suppressor cells was 23. The peculiar finding was erythrophagocytosis of the sheep red blood cells by the OKT4+ helper T lymphocytes. We assume that the production of lymphokines by the neoplastic T helper lymphocytes affects the OKT4+ cells themselves and induces a state of hyperactivation as shown by many protrusions and erythrophagocytosis by the malignant cells, simulating malignant histiocytosis. Furthermore, the patient T cells, in spite of their OKT4+ helper phenotype, showed suppressor activity.