The majority of patients with thymoma are asymptomatic at presentation with an incidentally discovered mass on imaging. Those who do present symptomatically have symptoms associated with local compression or invasion, such as chest pain, cough, or dyspnea. About one-half of patients with thymoma have MG and present with muscle weakness, diplopia, ptosis, or blurry vision. Lymphomas commonly present with “B-type” symptoms of fever, night sweats, weight loss, and malaise, in addition to mediastinal compression symptoms. Most patients with seminomas and nonteratomal nonseminomas present with systemic endocrine changes such as gynecomastia. In contrast, most patients with teratomas will have compression of nearby structures causing cough and dyspnea, or direct connection with the bronchial tree causing expectoration of teratoma contents.