[Tumor-node-metastasis classification for thymic epitherial tumors]

We applied the tentative TNM classification of thymoma to 24 cases of IV b thymoma, 59 cases of thymic carcinoma, and 26 cases of thymic carcinoma (109 cases in total). This classification was useful in these cases because cases could be divided into different grades (e.g. N 0, N 1, N 2, N 3) of the factor N (lymph node metastasis) without any shift to particular grades. Based on this finding, we hereby propose a TNM classification of thymic epitherial tumors which was prepared by slightly modifying the tentative TNM classification of thymoma.