Lymph node dissection in thymic malignancies

Lymph node metastasis is not uncommon and an important clinical parameter in thymic malignancies. It is consistently reported that lymph node metastasis is a poor prognostic factor in thymic malignancies (1-4). Original Masaoka stage classification system and latest International Association for the Study of Lung Cancer (IASLC)/International Thymic Malignancy Interest Group (ITMIG) stage classification system for thymic malignancies classify lymph node metastasis as stage IV (5,6). Understandings, however, about the details of lymph node metastasis in thymic malignancies such as incidence, lymphatic pathway, method of lymph node dissection (LND), and the benefit of diagnosis of lymph node metastasis are extremely limited until now.