If no tumor is found by bronchoscopy and pathology, further relevant investigations, such as tumor marker examination, chest enhancement CT, can be performed according to the patient’s medical history under the guidance of the doctor, and if necessary, another bronchoscopy or percutaneous puncture biopsy can be considered. Tumor markers are produced by tumor tissues and exist in tumor tissues, can also be secreted into the blood or body fluids in other areas, or produced by human cells stimulated by tumor tissues, and can be used as one of the markers for detecting and diagnosing tumors. Enhanced CT of the chest can examine the relationship between the large blood vessels in the chest and other organs and tissues in the chest, and can distinguish between tumors and soft tissue forms, which is very helpful in diagnosing tumors. Taking into account the patient’s medical history and other examination results, we may consider bronchoscopy or percutaneous puncture biopsy, or thoracoscopic biopsy to obtain certain pathological tissues, and ultimately to clarify the patient’s diagnosis. It is recommended that the patient should follow the doctor’s instructions for further examination to avoid delaying the condition.