The difference between cystadenoma and lung cancer is mainly manifested in the nature of the disease, clinical manifestations, treatment methods, etc. The former often has inconspicuous symptoms, while the latter may have chest tightness, hemoptysis, etc. The former grows slowly, while the latter grows more rapidly. 1. The nature of lung cystadenoma and lung cancer is different, the former is a benign disease, the latter is a malignant tumor. 2. The clinical manifestations of the two diseases are different. Cystadenomas in lungs usually have no symptoms, only larger cystadenomas may cause symptoms such as chest tightness, chest pain, etc. Generally, the symptoms of cystadenomas are mainly confined to the chest and grow slowly. Lung cancer can have chest symptoms such as cough, sputum, chest pain, etc. It grows more rapidly and can also have metastatic symptoms such as headache, abdominal distension and bone pain. 3. There is also a difference in treatments. Lung cystadenoma usually does not need treatment, and antibiotics such as amoxicillin need to be given to treat the combined infection. On the other hand, the treatment of lung cancer includes surgery, chemotherapy, targeted therapy, radiotherapy and other methods.