P64-5 A Case of Thymoma with Systemic Capillary Leak Syndrome That Responded to High-Dose Steroid Therapy

The case is a 74-year-old woman who was diagnosed with thymoma type B1 by CT-guided needle biopsy of an anterior mediastinal tumor. She had been scheduled for surgery, but was transported to the emergency room because of sudden onset of respiratory distress. She had bilateral pleural effusions with pericardial effusion and severe generalized edema, and thoracic drainage was performed. Although her dyspnea temporarily improved with drainage, she developed acute heart failure and was treated with NPPV. Although the heart failure improved, the pleural effusion and edema did not improve even with high doses of diuretics. The cause of the pleural effusion and edema was unknown despite various examinations, and we suspected a tumor-associated syndrome of thymoma. We judged that it would be difficult to treat her with surgery or cytotoxic anticancer drugs, and administered only methylprednisolone out of CAMP (Cisplatin + Doxorubicin + Methylprednisolone), which is one of the standard chemotherapy regimen for thymoma, and prednisolone was continued as maintenance therapy. Thereafter, the thymoma shrank markedly, urine output gradually increased, and edema disappeared, although pleural effusion remained. Since the patient improved accompanying shrinkage of thymoma, we diagnosed systemic capillary leak syndrome as a tumor-associated syndrome. The systemic capillary leak syndrome induced by thymoma is very rare and we herein report the case that high doses of steroids were effective.