Primary intrapulmonary thymoma: a systematic review

This article reviews the literature on the clinical features, diagnosis and management of primary intrapulmonary thymoma.

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.

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).

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.