Primary intrapulmonary thymoma: A systematic review

Aim This article reviews the literature on the clinical features, diagnosis and management of primary intrapulmonary thymoma. Methods Medline, Embase and Cochrane Library searches were performed on all relevant Anglo-Saxon language articles. The search words included “primary pulmonary thymoma” and “intrapulmonary thymoma”. Secondary references were obtained from key articles. Prognostic and treatment strategies were analyzed by the Kaplan–Meier method, comparisons between curves were made using log rank test. Results The searches yielded 25 cases of primary intrapulmonary thymoma. Median follow-up was 9 months (1 day to 13 years). At follow-up, 14 patients were tumor free, one patient had a local recurrence 8 years after radiotherapy, one patient responded favorably to radiotherapy, six patients died and three patients were lost to follow-up. The presence of a paraneoplastic syndrome decreased survival (P = 0.02), however, histological subgroup (P = 0.216), clinical stage (P = 0.63) and tumor size (P = 0.288) did not affect survival. Survival in surgically managed patients was significantly better than in conservatively managed patients (P = 0.039). Adjuvant radiotherapy did not provide any benefit (P = 0.4). Conclusion Complete resection of primary intrapulmonary thymomas appears sufficient in non-malignant tumors. Because of the risk of late local recurrence, long-term regular clinical follow-up is warranted.