Approximately 30% of patients with thymoma or thymic carcinoma have no symptoms when the tumor is diagnosed. These are typically detected when doctors are looking for other things, during routine chest x-rays, for example. Possible symptoms are listed in table 1.
| Persistent coughing |
| Chest pain |
| Upper airway congestion |
| Muscle weakness* |
| Fatigue* |
| Shortness of breath |
| Arm or facial swelling |
| Difficulty swallowing* |
| Anemia (low red blood cell count) |
| Increased risk of infection |
Table 1. Possible symptoms of thymic epithelial tumors
* these symptoms may be related to myasthenia gravis (meaning severe muscle weakness) which may be the presenting sign of thymoma