The Ninth Edition TNM Staging Classification for Thymic Epithelial Tumors

Staging classification is essential in cancer management and is based on three components: tumor extent (T), lymph node involvement (N), and distant metastatic disease (M). For thymic epithelial malignancies, clinical Tumour, Node, Metastasis (cTNM) staging is primarily determined by imaging, making radiologists integral to clinical practice, treatment decisions, and maintaining the quality of staging databases. The ninth edition of the TNM classification for thymic epithelial tumors will be implemented in January 2025. This review outlines the definitions for the TNM categories in the updated edition, provides examples, and elaborates on the radiologist's role and imaging considerations.