New perspective to evaluate N1 staging: The peripheral lymph node metastasis status of non-small cell lung cancer.

PLN metastasis was a quite common pattern of LN metastasis in N1 station of NSCLC. IPLNM occurred more frequently in central NSCLC and NSCLC with vascular invasion, and thoracotomy was likely to secure more accurate PLN staging. Clinicians should pay great attention to PLN dissection. Follow-up data will be needed in order to detect the prognosis of IPLNM patients.