術前診断に難渋した縦隔海綿状血管腫の 2 例

Background. Cavernous hemangioma in the mediastinum is relatively rare, accounting for !0.5% of all mediastinal tumors. Case 1. A 72-year-old woman was found to have an abnormal shadow at a medical examination. Chest computed tomography showed a 27-mm lobulated nodule in the left anterior mediastinum. Paraganglioma and carcinoid were suspected. Paraganglioma was excluded through a careful examination. The intraoperative findings showed the tumor to be hemorrhagic, and the surface was red in tone. The tumor was thus suspected of being hemangioma. The phrenic nerve went through surface of the tumor, but we considered it benign, so the phrenic nerve was preserved, and the tumor was resected. Case 2. A 64-year-old man was found to have an enlarged left mediastinal shadow at a medical examination. Chest computed tomography showed a 60-mm nodule in the left anterior mediastinum and poor contrast effect. Thymoma was suspected, and extended thymomectomy was performed. Combined resection of the left phrenic nerve was performed because the nerve was involved with the tumor. The transmanubrial approach was required due to adhesion between the left brachiocephalic vein and the tumor. Conclusion. Mediastinal cavernous hemangioma presents with a variety of image findings, and a precise preoperative diagnosis can be quite difficult. However, cavernous hemangioma is an important differential diagnosis of mediastinal tumor.