Recurrent sternal thymoma after thymectomy by video-assisted thoracic surgery.

An 81-year-old man underwent thymectomy by video-assisted thoracic surgery for a mediastinal tumor. The pathological diagnosis was Masaoka stage II type B3 thymoma. Thirty-six months later, he presented with a growing mass on his anterior chest wall. Computed tomography showed a lobulated tumor in the sternum with bone destruction. Positron-emission tomography-computed tomography showed a maximal standardized uptake of 12.3 in the tumor. Core needle biopsy confirmed a metastatic sternal tumor from a type B3 thymoma. We partially resected the sternum and reconstructed the defect using an expanded polytetrafluoroethylene sheet. The patient has remained recurrence-free for 3 years after the second surgery.