The hilum is wider than the normal standard, with an oval depression in the center of the medial surface of the lungs called the hilus of lung,hilum pulmonis, which is the place where the main bronchus, pulmonary artery, and pulmonary vein, as well as bronchial arteries, veins, lymphatics, and nerves enter and exit the lungs. There is an oblong depression in the middle of the mediastinal surface called the hilum. The upper part of the right hilum consists of the right upper pulmonary artery and branches of the pulmonary vein, and the lower part consists of the right lower pulmonary artery; the left hilum consists of the left pulmonary artery and branches of the upper pulmonary vein. The left hilum is slightly higher than the right hilum in the posterior-anterior plethysmograph, and in the lateral plethysmograph, the right hilum is more anteriorly and the left hilum is more posteriorly. Abnormal changes such as increase or decrease in size indicate lesions. Lung cancer (Lung cancer occurs in the mucosal epithelium of the bronchial tubes, also known as bronchopulmonary cancer. Lung cancer generally refers to cancer of the parenchyma of the lungs and usually does not include mesodermal tumors of other cribriform origin, or other malignant tumors such as carcinoid tumors, malignant lymphomas, or tumors metastasized from other sources. There are four main basic treatments for lung cancer: surgery, radiotherapy, chemotherapy and targeted therapy. The optimal treatment varies for different stages and pathologic types of lung cancer). Or other lung-occupying lesions.