I. The recent concept of co-existence of tuberculosis and lung cancer pulmonary tuberculosis (Pulmonary tubercnlosis) and lung cancer (lung cancer) are both common lung diseases. With industrialization and environmental pollution, the incidence of lung cancer has increased significantly in recent decades, and the incidence age has become younger, with the incidence rate starting to rise at the age of 40 and reaching a peak at the age of 50; on the other hand, due to the widespread use of anti-tuberculosis drugs, the life expectancy of tuberculosis patients has increased. The etiology and pathogenesis of the coexistence of tuberculosis and lung cancer have not been fully elucidated. (1) A more objective view is that it is an opportunistic coincidence that the incidence of lung cancer has increased dramatically and that TB patients tend to become older, making the coexistence of the two increasing. (2) Most patients believe that tuberculous scarring is more likely to cause lung cancer, and the postoperative pathology of some patients with tuberculosis combined with lung cancer suggests that there is continuity between the nucleation of fine bronchial epithelial hyperplasia and cancer nests within the tuberculous scar tissue, and this change is very important to explain the complication of peripheral or fine bronchoalveolar carcinoma based on tuberculosis. (3) The main reason for the combination of active tuberculosis in lung cancer patients is that the tumor itself or due to radiotherapy for tumor, etc., damages the host immune mechanism causing tuberculosis activity. Both TB and lung cancer have common respiratory symptoms such as cough and sputum (dry cough), hemoptysis, fever, chest pain and shortness of breath. There are many similarities in clinical manifestations, and the coexistence of the two often does not easily attract the high attention of patients or even clinicians, leading to missed diagnosis and misdiagnosis and missing the best time for treatment. Summing up years of clinical experience, we believe that the appearance of symptoms that do not correspond to the lesion, such as irritating cough, blood in the sputum, fixed and persistent chest pain, fever (or even hyperthermia) without a clear cause, and progressive wasting in TB patients over 40 years of age who have already stabilized TB or active TB in the course of regular anti-TB treatment, should be considered as a coexistence of the two diseases and a red flag for early diagnosis. Dangerous signs, even if the sputum is positive, should not let down the vigilance. The common means of examination are sputum membrane exfoliation cell examination, review X-ray chest film, chest X-ray CT (for comparison with previous imaging data), fiberoptic bronchoscopy () lung puncture, etc., in order to confirm the diagnosis as early as possible. Fourth, treatment (1) confirmed cases, surgery is the first choice of treatment measures surgical formula according to the coexistence of the two diseases, the patient’s age, lung function and other circumstances to decide. (2) After the existing examination, the diagnosis is not confirmed, but indeed not ruled out, patients with coexisting lung cancer should also have their chests cut for examination from time to time when necessary. (3) Chemotherapy is considered the only effective adjuvant and palliative treatment for post-operative patients and those whose tumors have spread. (4) Radiotherapy may contribute to the deterioration or reactivation of pulmonary tuberculosis, so radiotherapy is not advocated for such patients. (5) Postoperative anti-TB should be based on the activity of the lesion: 3-6 months of anti-TB treatment for quiescent or stable carcinoma in the lung and 6-9 months for active lesions or longer depending on the adaptations.