First report of a B cell lymphoproliferative disorder arising in a patient treated with immune suppressants for severe aplastic anemia.

Aplastic anemia is a disorder characterized by pancytopenia and bone marrow hypocellularity. There is some evidence that aplastic anemia may be due to suppression of hematopoiesis by activated T-suppressor cells. Thus, immunosuppressive agents have been used as an alternative to bone marrow transplantation for treatment. We report on a unique case of a patient with aplastic anemia who was treated with a course of immunosuppression including cyclosporine (CSA), anti-thymocyte globulin (ATG), and prednisone. Five months after this treatment, the patient developed a B cell lymphoproliferative disorder which was successfully treated with radiation therapy. Prior reports of CSA-associated lymphoproliferative disorders have appeared in the literature as potential side effects of immunosuppression following transplantation. This is the first report of a lymphoproliferative disorder associated with immunosuppressive treatment of aplastic anemia in a nontransplant setting. Thus, when presenting options for treatment of aplastic anemia, lymphoproliferative disorders should be included as a rare complication of immunosuppressive therapy.