[Lung cancer and lymph drainage].

Lung cancer is lymphophile and may involve lymph nodes (LN) belonging to lung lymph drainage. LN metastases are figured within stations numbered 1 to 14. These stations are located along lymph vessels. The lymph vessels and the LN are forming together anatomical chains. Lymph vessels are valved and pulsatile and travel to the cervical venous confluence where they pour the lung lymph into the blood circulation. They may be totally or partly nodeless along their travel, anastomose with each other around the trachea, and connect with the thoracic duct within the mediastinum. Within the anatomical LN chains, LN are variable in number and in size from one individual to another. They may be absent from one or several stations of the international mapping. Stations are located along the anatomical chains: pulmonary ligament (9), tracheal bifurcation(8 and 7), right paratracheal (4R, 2R and 1), preaortic (5 and 6), left paratracheal (4L, 2L and 1). Station 3 is located on 2 differents chains (phrenic and right esophagotracheal). Station 10 are located at the beginning of the mediastinal lymph nodes chains. Each chain connects with the blood circulation, anastomoses with he neighbouring chains and behave as an own entity whatever the number of its LN. International station mapping misknowns this anatomy and occults the true pronostic value of lung lymph drainage.