The major prognostic factors of thymomas: about a Tunisian study of 100 cases

Thymomas are characterised by their rarity, histologic variability and peculiar patterns of recurrence. Herein, we present the experience of a single institution and aim to highlight the major prognostic factors of these tumours.

We present a retrospective study on 100 thymomas diagnosed between 1994 and 2011. Statistical analyses were performed using version 18.0 SPSS. The Kaplan Meier method was used to estimate survival, and survival curves were compared using the Log-Rank test. A p < 0.05 was considered statistically significant.

50 men and 50 women underwent surgical resection for thymoma. Radiologic findings highlighted a diagnosis of thymoma in 51% of cases. The thymomas were classified as stage I in 25 cases, stage II in 47 cases, stage III in 25 cases and stage IV in 3 cases. According to the WHO classification, tumours were classified as type A in 14 cases, type AB in 24 cases, type B1 in 17 cases, type B2 in 20 cases, type B3 in 8 cases, B1/B2 in 8 cases and B2/B3 in 9 cases. The mean survival of patients was 136 months. Age, sex, tumour size, WHO classification and Masaoka stage were evaluated as prognostic factors. Univariate analysis showed that the major prognostic factors were WHO classification (p = 0.019) and Masaoka Stage (p = 0.0001).

Our results place emphasis on the prognostic value of WHO classification and Masaoka stage in thymomas; in addition, the necessity of improving reproducibility of microscopic classification to avoid discrepancies among prognostic groups is highlighted.