Masaoka staging
Pronunciation: ma-sa-OH-ka
A staging system specific to thymic tumors that assesses local invasion and capsular involvement.
Full Definition
The Masaoka staging system, later modified as the Masaoka-Koga system, is the most widely used staging classification for thymic tumors. It divides disease into four stages based on the degree of local invasion: Stage I (completely encapsulated), Stage II (capsular invasion or adhesion), Stage III (invasion of neighboring organs), and Stage IV (pleural or pericardial dissemination or distant metastases). This staging system is crucial for prognosis and treatment planning, as it correlates well with surgical resectability and overall survival outcomes.
Usage
Usage note: Always specify 'Masaoka staging' rather than just 'staging' when discussing thymic tumors to avoid confusion with TNM.
In Context
- "The thymic tumor was classified as Masaoka stage IIa due to microscopic capsular invasion." — Pathology staging report
- "Masaoka staging remains the gold standard for thymic tumor prognostication despite the development of TNM classifications." — Clinical review article