The patient is 62-year-old female. When she was 43 years old, MG occurred. At age of 49 years thymoma was found and complete thymectomy (stage III) and postsurgical irradiation were performed. At age of 57 years pleural dissemination of the thymoma was found. Chemotherapy was effective but did not obtain total tumor cell kill. Though chemotherapy has been repeated for each tumor regrowth, the regimen used at first recurrence became ineffective and the interval between tumor regrowth became shorter. This year, when she is 62 years old, PRCA and hypogammaglobulinemia were accompanied with the forth tumor regrowth.