{"entity":{"id":"thymus-staging","kind":"term","name":"Thymic tumour staging (Masaoka-Koga and AJCC chapter 35)","aka":["Masaoka-Koga","Masaoka-Koga stage","Masaoka","Masaoka stage","thymoma staging","IASLC/ITMIG thymic staging"],"tldr":"Thymoma has long been staged by the Masaoka-Koga system, which asks whether the tumour has broken through its capsule and into nearby organs; TNM staging from the IASLC and ITMIG is the newer standard.","summary":"In the NCI's health professional summary, the Masaoka staging system of 1981, modified by Koga in 1994, is the most commonly used and is recommended by ITMIG: stage I, completely encapsulated with no capsular invasion under the microscope; II, invasion into surrounding fat or mediastinal pleura, or microscopic invasion into the capsule; III, invasion into neighbouring organs (pericardium, lung, great vessels); IVa, pleural or pericardial spread; IVb, spread through lymph or blood. For consistency the AJCC and UICC adopted a TNM system developed by the IASLC and ITMIG; AJCC chapter 35 (thymus) has a Version 9 protocol for 2025 in the AJCC 2026 table.","asOf":"2026-11-04","links":[{"label":"National Cancer Institute, Thymoma and thymic carcinoma treatment (PDQ), health professional version: stage information","url":"https://www.cancer.gov/types/thymoma/hp/thymoma-treatment-pdq"},{"label":"American College of Surgeons, AJCC Current Staging System 2026 (which chapters are 8th edition and which Version 9)","url":"https://www.facs.org/media/c5ik5tkr/ajcc-current-staging-system-2026.pdf"}],"tags":[],"related":["itmig-mrecist","ajcc-version-9","tnm-staging"],"cancers":["thymoma","thymic-carcinoma","thymic-epithelial"],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"category":"Clinical"},"route":"/terms/thymus-staging/","neighbours":{"term":[{"id":"ajcc-version-9","kind":"term","name":"AJCC Version 9 staging","route":"/terms/ajcc-version-9/"},{"id":"staging-systems","kind":"term","name":"Disease-specific staging and risk systems (FIGO, Ann Arbor, IPI, R-ISS, ELN, IMDC)","route":"/terms/staging-systems/"},{"id":"itmig-mrecist","kind":"term","name":"ITMIG modified RECIST for thymic tumours","route":"/terms/itmig-mrecist/"},{"id":"tnm-staging","kind":"term","name":"TNM staging","route":"/terms/tnm-staging/"}],"cancer":[{"id":"thymic-carcinoma","kind":"cancer","name":"Thymic carcinoma","route":"/cancers/thymic-carcinoma/"},{"id":"thymoma","kind":"cancer","name":"Thymoma (WHO types A, AB, B1, B2 and B3)","route":"/cancers/thymoma/"},{"id":"thymic-epithelial","kind":"cancer","name":"Thymoma and thymic carcinoma","route":"/cancers/thymic-epithelial/"}]}}