[Optimal treatment of intrathoracic extramedullary hematopoiesis resembling posterior mediastinal tumor; report of a case].

Intrathoracic extramedullary hematopoiesis is a rare condition accompanying chronic hematologic disease. We present a case of chronic gastric ulcer in which a posterior mediastinal mass was diagnosed as extramedullary hematopoiesis. We underwent video-assisted thoracoscopic resection safely and successfully. This procedure is relevant and safety procedure for differential diagnosis of patients who have chronic anemia with asymptomatic intrathoracic tumors.