Table 3 Differential diagnosis of primary mediastinal tumors
Thymic clear cell carcinoma | Thymoma with clear cell component | Mediastinal seminoma | Parathyroid carcinoma with clear cell component | |
|---|---|---|---|---|
Median age | 55 | 58 | 40 | 56 |
Clinical features | – | Accompanied with systemic sclerosis | Abnormal Β-hCG level | Abnormal PTH, serum calcium and phosphorus |
Histopathology | ||||
Common points | Islands and trabeculae of carcinoma cells with clear cytoplasm | |||
Different points | Sclerotic stroma often present | Transition with typical thymoma region | Large nucleoli and prominent lymphocyte infiltration | Invasive growth pattern with abundant vessels |
Essential IHC results | CK (+) | TdT (T cell+) | OCT3/4, PLAP, CD117, SALL4 (+) | PTH, CK, Syn, ChrA (+) |
Molecular changes | EWSR1-ATF gene infusion | – | Isochromosome 12p, 12q amplification | – |