ObjectiveTo explore the clinical pattern of intrapulmonary lymph node metastasis and the significance of No.13 and No.14 lymph nodes biopsy in patients with non-small cell lung cancer (NSCLC).MethodsThe clinical data of 234 patients with primary peripheral NSCLC who underwent systemic dissection of intrathoracic lymph nodes and intrapulmonary lymph nodes in the First Affiliated Hospital of Chongqing Medical University between 2013 and 2015 were retrospectively analyzed. There were 159 males and 75 females, aged 36-89 (61.35±8.57) years. Statistical analysis was performed accordingly on hilar (No.10), interlobar (No.11), lobar (No.12) and segmental (No.13 and 14) sites of the samples of N1 lymph nodes after surgery.ResultsA total of 3 019 lymph nodes of No.10-14 were dissected in 234 patients (12.9 per patient). The 263 lymph nodes were positive with a rate of 8.71% (263/3 019) and lymph node metastasisa occured in 99 patients with a rate of 42.31% (99/234), among whom there were 40 patients of N1 metastasis, 48 of N1+N2 metastasis and 11 of N2 skipping metastasis. Routine pathological examination demonstrated No.13 and No.14 lymph nodes metastasis in 16 patients with a rate of 6.84% (16/234). In 886 dissected lymph nodes of No.13 and No.14, 86 lymph nodes showed metastasis with a rate of 9.71% (86/886). Of the patients with swelling hilar and mediastinal lymph nodes reported by preoperative CT scan, only 56.32% of them were confirmed with lymph node metastasis by postoperative histopathology; while 34.01% of the patients with normal size lymph nodes had lymph node metastasis.ConclusionIn the surgical treatment of NSCLC, it is necessary to detect the metastasis of No. 13 and 14 lymph nodes and non-tumor parabronchial lymph nodes, which is helpful to obtain accurate postoperative TNM staging and is of great significance for guiding postoperative treatment. Preoperative CT is not a reliable method to judge lymph node metastasis, particularly for intrapulmonary lymph node metastasis.