Repeated sputum cytology examination is negative; if the supraclavicular metastatic lymph nodes are located too deep to be punctured, or if the tumor location is close to the chest wall and cannot be reached by bronchoscopy, or if the patient cannot tolerate bronchoscopy and the tumor location is suitable for puncture, lung puncture is needed to clarify the pathological diagnosis. Will lung puncture cause metastasis and spread of lung cancer? Theoretically, during lung puncture, the puncture needle passes through the soft tissue structures within the chest wall when withdrawing, which may leave behind the tumor cells carried inside the needle, thus causing the metastasis and spread of lung cancer. However, large international studies have proven that the chance of lung puncture biopsy causing metastasis and spread of lung cancer is very, very small and very rare.