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Masaoka staging system

Wednesday 7 December 2016


- Protocol for the Examination of Specimens From Patients With Thymoma and Thymic Carcinoma (Link)

Pathologic Staging for Thymomas (Modified Masaoka Stage) (applies only to thymomas)

- Stage I: Grossly and microscopically encapsulated (includes microscopic invasion into, but not through, the capsule)
- Stage IIa: Microscopic transcapsular invasion
- Stage IIb: Macroscopic capsular invasion
- Stage III: Macroscopic invasion of neighboring organs
- Stage IVa: Pleural or pericardial dissemination
- Stage IVb: Hematogenous


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