Postoperative recurrence of thymoma is unlikely, and the cause of recurrence is often due to factors such as insufficient resection scope during surgery. Thymoma is a common primary tumor in the anterior mediastinum, which may be detected without clinical symptoms during physical examination, or it may be detected by chest CT examination when some patients have obvious symptoms of myasthenia gravis, including weakness of limbs and ptosis. Since thymoma has the probability of malignancy, it is often found to require surgical resection. The thymus is a lymphatic organ that is often located in the anterior mediastinum, but an ectopic thymus can be located anywhere in the thoracic cavity from the thyroid gland to the diaphragm. Therefore, total thymectomy with mediastinal fat removal is required when thymoma surgery is performed; otherwise, an ectopic thymus can lead to non-resolution of symptoms, resulting in a postoperative clinical recurrence.