Masaoka staging system of thymoma

The Masaoka staging system is commonly adopted for thymomas 1-3, and is the most important determinant of survival following surgical resection 4:

  • stage I: intact thymic capsule
  • stage II: capsular invasion into adjacent mediastinal fat or pleura
  • stage III: macroscopic invasion into adjacent organs, vessels
  • stage IV
    • IVa: dissemination in thoracic cavity (i.e. pleural or pericardial implants) 
    • IVb: distant metastases

Stage II and above are regarded as thymic carcinoma 2.

Share Article

Article Information

rID: 7812
Systems: Chest, Oncology
Section: Staging
Tag: stub
Synonyms or Alternate Spellings:
  • Thymoma staging

Support Radiopaedia to see fewer ads

  • Drag
    Case 1
    Drag here to reorder.
  • Drag
    Case 2: stage I
    Drag here to reorder.
  • Updating… Please wait.
    Loadinganimation

    Alert accept

    Error Unable to process the form. Check for errors and try again.

    Alert accept Thank you for updating your details.