Abstract
A 69-year old woman received the diagnosis of an anterior mediastinal tumor of 15 mm in diameter and was followed up 5 years ago. She suddenly developed a chest pain and cough, and chest CT showed that the tumor diameter had increased to 31 mm and showed inflammatory findings. However, the tumor had reduced to 19 mm on chest CT after 2 weeks. Because the cause of the inflammatory change was unknown and was relapse a possibility, we decided on an operative strategy. We performed partial thymectomy by median sternotomy. The pathological diagnosis was thymic cancer but mostly necrotic tissue, and the surgical margin was negative. She was followed up closely without treatment.
