Predictors of recurrence in thymic tumors: Importance of invasion, World Health Organization histology, and size

The Masaoka staging system could be collapsed to 3 degrees of invasion by combining stages I and II. The World Health Organization histologic type can be simplified for clinical use into A (A, AB), early B (B1, B2), advanced B (B3), and C tumors. Size of 8 cm or larger is an independent risk factor, even when patients with Masaoka stage III tumors are considered alone, and might identify candidates for preoperative therapy.