The severity of a 0.6 cm mediastinal nodule is determined primarily by the cause of the nodule. A small lymph node alone is not serious; a metastatic tumor or thymoma is a more serious condition. 1. Under normal circumstances, there are small lymph nodes in the mediastinum, which are normal or enlarged due to inflammation, usually with no obvious clinical symptoms, and the corresponding condition is not serious. 2. If there is a history of primary tumor, and the 0.6 cm mediastinal nodule is new, there is a possibility of metastatic tumor, which is more serious and needs further judgment; the 0.6 cm mediastinal nodule is located in the thymus gland, and accompanied by myasthenia gravis, which may be thymoma, which is also a more serious condition and needs surgical treatment. On the whole, mediastinal 0.6 cm nodule needs to be combined with clinical history and symptoms to make a comprehensive judgment, and after confirming the specific condition, standardized treatment should be carried out under the guidance of clinicians.