Secondary malignant tumors of the hilar mediastinal lymph nodes are treated differently depending on the tumor. Surgery is recommended for secondary thymoma, while lymphomas are often treated with radiotherapy and chemotherapy. Secondary malignant tumors of the mediastinal lymph nodes are either lymphomas or thymomas. Thymoma is more differentiated and can be cured by surgical resection with a better prognosis. Lymphoma, however, is more malignant and more difficult to treat, and is usually treated with an integrated approach combining radiotherapy and chemotherapy. Radiotherapy and chemotherapy can mainly remove the residual cancer cells in the body, control the progression of advanced cancer, reduce the cancer lesions within a certain range, and improve the survival time and quality of life of patients. However, it should be noted that lymphoma secondary to mediastinal lymph nodes should be regularly reviewed after surgery to prevent tumor recurrence and metastasis.