[A case of teratoma in both the mediastinum and the intrapulmonary system]

A rare case of mature teratoma in both the mediastinum and the intrapulmonary system is presented. A 30-year-old male was admitted to our hospital due to tumor masses in the mediastinum and the left lung. We performed mediastinal tumor resection and left upper partial lobectomy. Neither tumor communicated with each other. Pathological findings revealed teratoma in the mediastinal lymph node and the intrapulmonary system including no malignant cells in either tumor. In this case, because metastasis and perforation were negative, we proposed that both tumors occurred at the same time in the early embryo.