Recently, we encountered two younger patients in a row, in their 40s, which is a time of heavy burden for the elderly and the young. One was considered a mediastinal teratoma and the other a pancreatic dystrophy, both benign at the beginning, with a history of more than 30 years, which remained untreated until the disease worsened and then they came to the clinic. The former teratoma malignant, pericardial metastasis, only palliative surgery, the latter combined with esophageal cancer to do esophageal subtotal resection. If the surgical treatment is done early one is effective and basically does not affect the life span, while the total cost is less and does not come to the current situation. It is recommended that we should not have such a misunderstanding that benign lesions can be left alone, but should listen to the advice of professional physicians and deal with them as early as possible to prevent tragedies from happening. Similar diseases in the chest mainly include: 1, mediastinal cyst; 2, bronchiectasis; 3, reflux esophagitis; 4, lung abscess; 5, myasthenia gravis; 6, spontaneous pneumothorax; 7, encapsulated abscess chest, etc.