BACKGROUND

although rare, thymomas are the most common tumors of the thymus in adults. They represent about 20% of all mediastinal tumors.

AIM

the aim of this study is to present clinicopathological features of thymomas in Tunisia and analyse the prognostic factors.

METHODS

From 1993 to 2004, clinical data of 40 cases of thymomas were compiled retrospectively. Microscopic slides were reviewed and reclassified according to the WHO classification of thymic tumors 2004. Clinical staging adopted was Masaoka system. Analysis of survival was determined by Kaplan-Meier method and log-rank test was used to compare survival curves. These statistical analyses were performed by SPSS.

RESULTS

they were 23 women and 17 males of ages ranging from 14 to 76 years (mean age 51 years). The distribution of histological WHO types was: 1 type A, 7 type AB, 6 type B1, 17 type B2, 6 type B3, 2 cases of micronodular thymoma with lymphoid stroma and 1 case of metaplastic thymoma. According to Masaoka stage, 10 patients were in stage I, 11 stage II, 9 stage IIIa, 4 stage IIIb, 5 stage Iva and 1 stage IVb. The average overall survival was 56 months. Univariate analyses showed that Masaoka stage, completeness surgical resection and age were prognostic factors whereas in multivariate analysis, age was the only prognostic factor. Neither myasthenia gravis nor histological WHO subtypes had effect in survival.

CONCLUSION

masaoka stage, completeness surgical resection and age are the prognostic factors predicting survival in our series.