[Mediastinal hematoma due to thymoma hemorrhage--a case report].

A 70-year-old man came to our hospital complaining mainly of acute dyspnea. A chest X-ray, echocardiogram, and chest CT showed a mediastinal mass, and pericardial and pleural effusions. A thoracotomy revealed a cystic tumor along the thymus. The tumor contained bloody fluid, coagula, and fibrin calculi. Rapid specimens showed no tumor cells and the hematoma was assumed to have been caused by the thymus. Therefore, a thymectomy was performed and as much of the hematoma as possible was removed. After the operation, a careful pathological examination revealed a thymoma with a diameter of about 7 mm. In addition, coagula and fibrin calculi contained some tissue from the thymoma, and the diagnosis was made that a mediastinal hematoma had formed due to hemorrhage from the thymoma. Several cases of mediastinal tumor of cyst hemorrhages in the thorax have been reported. However, only a few cases of thymomal hemorrhages in the thorax have been reported; one case each of mediastinal hematoma, hemothorax, and cardiac tamponade. Great care is necessary when dealing with atraumatic mediastinal hematomas if malignant tumors such as thymoma are present.