Skip Mediastinal Lymph Node Metastasis and Lung Cancer: A Particular N2 Subgroup With a Better Prognosis

(N1−)N2 skip metastasis is a unique subgroup of pN2 disease. Lung lymph drainage anatomy may explain the occurrence of these metastases. They form an independent prognostic factor of survival suggesting the need for further study, the results of which may lead to better knowledge of lung cancer, improved classification, and adapted adjuvant therapy.