Background: Thymectomy can effectively cure most thymoma patients
however, patients with advanced thymoma typically require chemotherapy, which is associated with limited efficacy in this context. Here we provide the first report of a patient with recurrent thymoma who achieved complete remission (CR) using cyclosporine therapy. Case presentation: A 63-year-old woman who had undergone resection surgery for recurrent type B1 thymoma developed pure red cell aplasia (PRCA), and CT findings revealed thymoma recurrence. After the initiation of orally-administered cyclosporine, PRCA quickly resolved, and the thymoma disappeared without the administration of any anti-thymoma therapy. The patient has remained in CR for over 3 years using only cyclosporine. Conclusions: This is the first report describing the curative potential of cyclosporine for the treatment of advanced thymoma. Although the mechanism underlying this effect remains unclear, cyclosporine can become a less toxic and more cost-effective treatment option for thymoma compared with conventional therapy. Clinical trials are needed to confirm the therapeutic potential of cyclosporine as a new treatment option for thymoma.