The complications of thymoma are as follows: 1, myasthenia gravis For a long time, it has been found that myasthenia gravis is related to thymoma. Myasthenia gravis can be clinically divided into 3 types, such as eyelid ptosis, long-lasting fatigue, diplopia, etc. for the ocular muscle type; upper limb extension and lifting can’t be sustained, and need to sit down and rest for the trunk; chewing and swallowing is difficult, and even paralyze the whistling muscle for the medulla oblongata type. The most dangerous clinical situation is myasthenia gravis crisis, patients with paralyzed sucking muscles must be artificially assisted to suck. At present, it is believed that myasthenia gravis is an autoimmune disease, mainly due to the thymus gland by some kind of stimulation of mutation, for many years has been used to treat myasthenia gravis with anti-acetylcholinesterase drugs, such as pyridostigmine, and in recent years, it also added immunosuppressant drugs, such as hormones, cyclophosphamide and so on. 2.Pure red cell aplastic anemia One of the coexisting diseases with thymoma is pure red cell aplastic anemia. Pure red aplastic anemia can be primary, the reason is not clear, also can be secondary to drugs, infection and tumor. 3, nephrotic syndrome nephritis The relationship between nephrotic syndrome nephritis and thymoma is unknown. Nephrotic syndrome can be part of the systemic manifestations of certain tumors, such as Hodgkin’s disease. A possible explanation is that thymoma forms a cross-reaction with antigen-antibody complexes in glomerulonephritis. Principles of treatment of thymoma: Thymoma should be surgically removed as soon as it is diagnosed. Both benign and malignant thymoma should be removed as early as possible. The resected malignant thymoma can be guided by pathologic biopsy for postoperative treatment, and postoperative radiation therapy for partially resected thymoma can alleviate the symptoms and prolong the survival time of patients. Problems that should be noted during surgery for thymoma: benign thymoma that is isolated and without adhesion can be removed without difficulty, and the surgery can be completed successfully, but the difficulties should be fully estimated during surgery for some complicated cases. Malignant thymoma should be explored first to clarify the relationship between the tumor and the surrounding adjacent organs before dissection. Thymoma is located at the base of mediastinum, the junction of heart and blood vessels; malignant thymoma infiltrates into the surrounding adhesions; when the tumor grows, the neighboring tissues and organs are pushed away, and the normal anatomical relationship is changed; the fibrous connective tissue adhesions are thickened, so that it is not easy to distinguish with blood vessels, which may cause the blood vessels being injured by mistake in the operation, and then lead to haemorrhage.