Lung metastasis of adenoid cystic carcinoma of submandibular gland sometimes has no obvious clinical symptoms, but sometimes there are cough, sputum, hemoptysis and so on, and sometimes there may be clinical symptoms such as chest tightness, breathlessness, chest pain and so on. 1. No obvious clinical symptoms: if the lung metastasis of adenoid cystic carcinoma of submandibular gland does not invade the larger parts of bronchus and pleura, there may be no obvious symptoms, and it is often found during chest CT examination. 2. Cough, sputum, hemoptysis: when adenoid cystic carcinoma submandibular gland lung metastasis stimulates bronchial tubes, irritating cough may appear, sometimes accompanied by sputum, and when the tumor is necrotic and hemorrhagic or invades blood vessels and bleeds, blood in sputum or hemoptysis may appear. 3. Chest tightness, breathlessness, chest pain: lung metastasis of adenoid cystic carcinoma of submandibular gland may have chest tightness if it invades pleura and pleural effusion occurs, breathlessness may occur when the amount of effusion is large, and there may be chest pain if it invades chest wall. In addition to the above clinical symptoms, there may also be systemic manifestations such as fatigue, weight loss, etc. It is recommended that patients should consult hospitals in time and under the guidance of doctors for disease evaluation and treatment.