Solitary thymic metastasis of breast cancer 13 years after surgery

A 59-year-old woman was noted to have an anterior mediastinal mass on computed tomography at a regular follow-up 13 years after initial surgery for left breast cancer. Magnetic resonance imaging showed an anterior mediastinal mass. A total thymectomy with excision of surrounding lymphoid tissue was performed. Pathological examination of the resected tumor confirmed the diagnosis of thymic metastasis from breast cancer. The patient has been alive for 6 years after thymectomy. Metastases to the thymus are rare, but long-term survival can be expected with appropriate treatment.