A 52-year-old woman was admitted to our hospital with the diagnosis of an unenhanced middle mediastinal tumor on the right side of the heart and enlargement of the superior vena cava (SVC) as an incidental finding on a chest and abdominal CT during an examination for abdominal pain. We performed a thoracoscopic biopsy of the tumor, which was hemorrhagic and was present from the lower part of the SVC to the top of the diaphragma. The tumor was diagnosed as cavernous hemangioma according to the pathological examination. The incidence of mediastinal hemangioma is less than 0.5% of all mediastinal tumors, and middle mediastinal hemangioma is very rare. Therefore, we herein report this rare case of middle mediastinal hemangioma with enlargement of the SVC.
