Anatomical pathways of lymphatic flow between lung and mediastinum.

The knowledge of anatomical lymphatic drainage pathways between lung and mediastinum and metastatic spread patterns of lung cancer forms the basis for the modern TNM classification for the staging of lung cancer. Clinical and anatomical studies divided pulmonary nodes into intrapulmonary and bronchopulmonary, the latter distinguished into lobar and hilar nodes. Mediastinal nodes are grouped into anterior prevascular, tracheobronchial, paratracheal and posterior nodes. The different pathways of lymphatic drainage of the lungs to the mediastinal lymph nodes are presented with the consequent surgical implications.