Posttransplant lymphoproliferative disorders are lymphoid proliferations or lymphomas, usually associated with Epstein-Barr virus infection, that develop as the consequence of immunodepression. These disorders usually affect patients receiving high doses of cyclosporine in the context of bone marrow or organ transplantations. Posttransplant lymphoproliferative disorders can regress when cyclosporine is discontinued. Such lymphoproliferations rarely occur for patients receiving low-dose cyclosporine treatments for autoimmune disorders. In the following report, we describe a patient with psoriasis vulgaris treated with long-term low-dose cyclosporine who developed an acute Epstein-Barr virus–associated clonal lymphoproliferative disorder associated with hemophagocytic syndrome. This lymphoproliferative disorder resembling classic posttransplant lymphoproliferative disorder regressed when cyclosporine was discontinued.