There is a large homogenous soft tissue mass occupying the superior mediastinum extending from the origin of the great vessels to the thoracic inlet. The mass encases without compressing the aorta, pulmonary trunk and the trachea. The mass bulges to the left and mildly displaces the medial left upper lobe, causing some compressive atelectasis with patchy ground glass opacity. There further patchy ground glass opacities in the posterior basal segment of left lower lobe.
Several small left sided pleural plaques identified. A plaque related to the pericardium posterior surface may be calcified.
Conclusion:
Large homogenous soft tissue mass in the superior mediastinum with left pleural disease. Possibilities include lymphoma or less likely thymoma.