Solitary extramedullary plasmacytoma located in the thorax is a rare tumor. We present a 21-year-old patient who was diagnosed with a mediastinal solitary extramedullary plasmacytoma. Complete resection of the tumor with reconstruction of the right pulmonary artery and superior vena cava was performed. The patient is alive without evidence of recurrence 8 months after the operation. Extensive resection and reconstructive surgery with the addition of radiotherapy can prolong the patient's life.