There are very few malignant lung proliferative lesions. Proliferative lesions in the lungs are mainly described pathologically in imaging of both lungs by radiographs, CT or MRI. Clinically, most proliferative lung lesions are benign, such as those caused by inflammation, including viral, bacterial, Mycobacterium tuberculosis, fungal, and protozoal infections, as well as inflammatory pseudotumors and idiopathic interstitial lung fibrosis from various causes. Only a very small percentage of pulmonary proliferative foci are malignant, such as bronchopulmonary carcinoma, and a small percentage of benign tumors result from malignant transformation. Clinically, it is necessary to review the CT of both lungs, and bronchial fiber endoscopy can be used to take biopsies from the lesions for pathological examination to clarify the disease and its cause and enable timely treatment.