Two cases of thymoma with pulmonary metastasis: a case report

BACKGROUND: Pulmonary metastases of thymomas are relatively rare. We report on two patients who underwent surgery for resection of pulmonary metastases. METHODS AND RESULTS: One patient was a 74-year-old man. A chest CT scan showed a mediastinal mass and a hilar nodule in the left lung. The patient underwent surgical resection of both of these lesions. The histological diagnosis was type A thymoma with intrapulmonary metastasis, classified as stage IVb. He did not receive any adjuvant therapy following the operation because the resection was complete. There has been no evidence of recurrence in four years. The other patient was a 68-year-old man with myasthenia gravis. At the age of 61 years, he underwent extended thymectomy with combined resection of the surrounding involved structures. The histological diagnosis was type B3 thymoma, stage III. Adjuvant radiation (40 Gy) was administered postoperatively; however, a pulmonary nodule occurred seven years following the initial operation (patient age, 68 years). He subsequently underwent right lower lobectomy and a diagnosis of intrapulmonary metastasis of thymoma was made. There has been no evidence of recurrence in two years. CONCLUSIONS: Long-term follow-up is important to detect recurrence in any cases of thymoma. Lung metastases should be operated upon if they appear to be completely resectable and this can achieve long-term survival.