TABLE 1

Staging of thymic tumours according to 8th Tumour Node Metastasis (TNM), and Masaoka–Koga staging systems

StageDescriptors
Tumour
 T1T1aEncapsulated or unencapsulated, with or without extension into the mediastinal fat
T1bExtension into the mediastinal pleura
 T2Direct invasion of the pericardium (partial or full-thickness)
 T3Direct invasion of the lung, the brachiocephalic vein, the superior vena cava, the chest wall, the phrenic nerve, and/or hilar (extrapericardial) pulmonary vessels
 T4Direct invasion of the aorta, arch vessels, the main pulmonary artery, the myocardium, the trachea, or the oesophagus
Node
 N0N0 No nodal involvement
 N1N1 Anterior (perithymic) nodes (IASLC levels 1, 3a, 6 and/or supradiaphragmatic/inferior phrenics/pericardial)
 N2N2 Deep intrathoracic or cervical nodes (IASLC levels 2, 4, 5, 7, 10, and/or internal mammary nodes)
Metastasis
 M0No metastatic pleural, pericardial, or distant sites
 M1M1aSeparate pleural or pericardial nodule(s)
M1bPulmonary intraparenchymal nodule or distant organ metastasis
Stage groupingCorresponding Masaoka–Koga stage
 IT1N0M0I, IIA, IIB, III
 IIT2N0M0III
 IIIaT3N0M0III
 IIIbT4N0M0III
 IVaT any N0,1 M0,1aIVA, IVB
 IVbT any N0-2 M0-1bIVB
  • IASLC: International Association for the Study of Lung Cancer.