A large (roughly 9 x 9 x 14 cm) anterior mediastinal soft density mass is noted without internal calcification. The lungs, heart and superior mediastinum appear unremarkable. No osseous lesion identified.
Large anterior mediastinal mass may represent lymphoma (most likely) or a thymic tumour, metastatic nodal mass, vascular anomaly etc...
This needs prompt further assessment with contrast enhanced CT scan.