Lung biopsy: Lung biopsy is percutaneous lung aspiration biopsy (TTNA), which is used for the diagnosis and differential diagnosis of peripheral lung lesions or diffuse lung lesions, and its indications are: 1. Shenyang Chest Hospital, Department of Oncology, Li Yin Yin 2, diffuse lung lesions of unknown origin, percutaneous lung biopsy can be done under the condition of pleural adhesions. 3.Limited pulmonary infiltrates. 4, mediastinal mass of unknown cause. Normal values for lung biopsy: Normal lung tissue. Clinical significance of lung biopsy: 1. Tumor cells seen on histopathological examination of lung biopsy can confirm the diagnosis of tumor. 2. Histopathological examination of lung biopsy reveals tuberculosis granuloma, which confirms the diagnosis of tuberculosis. 3, inflammatory lesions seen on histopathological examination of lung biopsy, considered as lung infection. Contraindications to lung biopsy are: 1, severe cardiopulmonary insufficiency. 2, pulmonary vascular lesions. 3. Those with bleeding tendency. 4.Acute infection of the respiratory tract with fever. 5.The patient is uncooperative or has uncontrollable cough. Possible complications of lung biopsy: 1. Pneumothorax: the most common, but most are small amounts of pneumothorax, which usually do not require treatment. 2, hemothorax and hemoptysis: a few cases can occur, but massive bleeding is rare. 3.Thoracic infection: mostly seen in those with severe infection of original respiratory tract and lung, which is safer to be carried out after effective antibiotic treatment. 4. Needle tract implantation of cancer cells. It can be effectively avoided with trocar needle technique.