Primary leiomyosarcoma of the anterior mediastinum encasing the aortic arch, left common carotid and left subclavian arteries.

A 66-year-old man presented with a one month history of hoarseness. Left recurrent nerve palsy and a left upper mediastinal mass were observed by an otorhinolaryngologist who referred the patient to our department. Chest computed tomography showed a superior mediastinal mass, which seemed to involve the left common carotid and left subclavian arteries from the greater curvature of the aortic arch. The innominate vein was compressed, and collateral circulation was well developed. The left upper lobe of the lung was also seemed involved. A mediastinal biopsy conducted via left thoracoscopy revealed a malignant spindle cell tumor. The mediastinum was irradiated (40 Gy), and surgical extirpation was subsequently undertaken 3 weeks later. The tumor was successfully removed without the use of extracorporeal circulation. Because only smooth muscle actin was focally but strongly expressed immunohistochemically, leiomyosarcoma was confirmed. The patient was discharged on day 14. A solitary left pleural metastasis was observed and resected 12 months after the surgery and the patient is well without further recurrence 16 months after the initial surgery.