During the treatment of thymoma, we find that two common problems often plague patients: one is severe myasthenia gravis in the perioperative period of thymoma, and the other is the distinction between benign and malignant thymoma. Indeed, these are two relatively complex and difficult issues for patients with thymoma to understand, yet they cannot be completely avoided in the treatment process. The relationship between myasthenia gravis and thymoma can be a bit of a mystery, as studies have found that 15-30% of patients with myasthenia gravis have thymoma and 30%-60% of patients with thymoma have myasthenia gravis, but there is no necessary correlation between the two, as it is the dysfunction of the immune system that allows both diseases to appear in patients. The real reason for physicians and patients to pay attention to the combination of myasthenia gravis in thymoma is the fear of myasthenia gravis after thymectomy: the inability of the patient to breathe on his own due to weakness of the respiratory muscles (how annoying is it to not be able to breathe?). Therefore, our thoracic surgeons usually carefully assess the possibility of myasthenia gravis in the postoperative period in several ways. First, we will find out whether the patient has the experience of morning lightness and evening weakness, which is aggravated by activity and reduced and relieved by rest (that is, medical history, not concealing medical history will help to diagnose and treat the disease). Next, serum acetylcholine receptor antibodies, prominent anterior membrane antibodies, and thymoma-associated antibodies will be checked preoperatively to assess immune system function. If the history and serum tests make us suspect that the patient has symptoms of muscle weakness we will further examine the patient’s electromyography and nerve conduction function. Finally, we will evaluate the patient for the presence of myasthenia gravis and the possibility of postoperative myasthenia crisis in conjunction with the neurologist. If myasthenia gravis is present, the patient will receive regular preoperative treatment and then undergo thymoma surgery to reduce the risk of postoperative myasthenia gravis. Good and thorough preoperative evaluation and treatment can reduce the probability of postoperative myasthenia gravis crisis. The good news is that pathologists have stopped writing malignancy on pathology reports for thymoma for a long time, and the bad news is that your surgeon may be very serious about telling you that you need long-term post-operative follow-up or more annoying radiotherapy. What’s going on? To understand what is going on, you need to know what the doctors are doing. The pathologist’s job is to histologically grade thymomas, which are classified according to World Health Organization (WHO) criteria as: A medullary thymoma; AB mixed thymoma; B1 cortical-dominant thymoma; B2 cortical thymoma; and B3 epithelial thymoma (C thymic carcinoma is not discussed here). Although the pathologists found through the microscope that heterotypic cells (bad cells) could already be seen in B-type thymoma, they did not meet the criteria for determining it as a malignant tumor, so the pathology report could only helplessly give the conclusion that it was similar to moral corruption and had not yet broken the law. However, the thoracic surgeons working in the front line of clinical practice could be very dissatisfied with such a decision (understandably, the bad guys who had worked hard to catch the tumor were let go by the pathologist), so Masaoka and colleagues proposed a clinical staging based on the growth pattern of the tumor during surgery: I tumor with intact envelope seen with the naked eye; IIa tumor invasion seen under the microscope; IIb tumor invasion around the naked eye Masaoka’s staging has been unanimously accepted and promoted by thoracic surgery colleagues and applied to the postoperative treatment follow-up of patients with good results (isn’t it?). there is a feeling of the net of heaven?) Therefore, please remember that the histological staging of thymoma patients needs to be combined with the clinical presentation to better guide the postoperative treatment.