Multicentric Castleman's disease is a systemic inflammatory disorder characterized by lymphadenopathy and excessive interleukin-6 production. A unique clinicopathologic variant of multicentric Castleman's disease, TAFRO (i.e., thrombocytopenia, anasarca, fever, renal failure or reticulin fibrosis, and organomegaly) syndrome, was recently proposed in Japan. Despite the successful use of anti-interleukin-6 therapy in some patients with TAFRO syndrome, not all patients achieve remission. The pathophysiological etiology of and suitable therapeutic strategies for this variant have not been established. Here, we present our experience of a unique case of TAFRO syndrome in a 78-year-old woman whose symptoms responded differently to several therapies. Tocilizumab, an anti-interleukin-6 receptor antibody, successfully induced remission of fever and lymphadenopathy. However, severe thrombocytopenia persisted and she developed anasarca, ascites, and pleural effusion shortly thereafter. Rituximab, an anti-CD20 antibody, and glucocorticoid therapy provided no symptom relief. In contrast, cyclosporine A, an immunosuppressive agent that blocks T cell function by inhibiting interleukin-2, yielded immediate improvements in systemic fluid retention and a gradual increase in platelet count, with complete resolution of disease symptoms. Excessive serum interleukin-2, when used as an anti-cancer agent, has been reported to cause side effects such as fluid retention, thrombocytopenia, and renal failure. Our case was unique because the anti-interleukin-2 therapy successfully improved symptoms that were not relieved with anti-interleukin-6 therapy. The present report therefore provides insight into the possible role of interleukin-2, in addition to interleukin-6, in TAFRO syndrome. This report will certainly help to clarify the pathogenesis of and optimal treatment strategies for TAFRO syndrome.