[Schwannoma originating from a mediastinal vagal nerve resected by video-assisted thoracic surgery: a case report].

A 63-year-old man was referred to our hospital due to an abnormal shadow found on a chest CT scan. The CT scan showed a cystic tumor with a central high density in the right upper mediastinal area. The preoperative diagnosis was teratoma in the right upper mediastinal area. Video-assisted thoracic surgery was performed. The tumor was about 3cm in size and originated from the right vagal nerve. Microscopic findings of the resected specimen showed loose growth of spindle cells, in which a myxomatous framework was observed in the peripheral area as well as extended vessels, with thrombis, Verocay bodies, and a nuclear palisading pattern confirmed in the central area. The histological diagnosis was schwannoma originating from the mediastinal vagal nerve. This case was thought to be rare and difficult to diagnose by preoperative imaging findings. Postoperative hoarseness due to dysfunction of the right recurrent nerve occurred. Careful consideration should be given to the indication of video-assisted thoracic surgery for neurogenic mediastinal tumors since postoperative dysfunction may occur.