Accounting for 30% of mediastinal masses: (4 T’s)
- Thymoma
- Teratoma
- Thyroid (ectopic)
- (Terrible / multicentric) lymphoma [Hodgkin] [Non-Hodgkin] (most common anterior mediastinal mass)
- (and prominent thymus)
Approach to the differential diagnosis of anterior mediastinal mass:
- Determine if what you are seeing is a prominent thymus with symmetrically enlarged thymic lobes, if the thymic lobes are asymmetrically enlarged then consider thymoma
- If there is fat or calcium in the mass, consider teratoma
- If the thyroid is absent from its normal position in the neck, consider ectopic thyroid and a nuclear medicine scan
- Otherwise surmise the mass is a lymphoma and determine where best to biopsy
Pediatric Imaging 