To determine whether mediastinal tumor is in early or late stage, it is mainly through imaging examination and the presence of peripheral compression symptoms. 1. Imaging examination: through CT examination, the location and size of the tumor can be clarified; through abdominal CT examination, whether there is abdominal metastasis or not can be understood; if metastasis occurs, the possibility of advanced stage is high. 2. Whether there are symptoms of peripheral compression: in the advanced stage of mediastinal tumor, peripheral compression symptoms may appear. If the tumor compresses the esophagus, it may cause uneasiness in eating, difficulty in swallowing, or even completely unable to swallow food. Pressure on the recurrent laryngeal nerve may cause hoarseness. Compression of the superior vena cava may result in edema of the upper extremities, face and neck. According to the stage, choose the appropriate treatment plan, specific can consult the professional physician’s opinion.