A 68 year old man came with complaints of acute severe chest pain post CAG.
The frontal chest radiograph shows a well defined soft tissue density lesion in the left mid and lower zones with a broad base towards the mediastinum. The mediastinal vessels are seen coursing through it. The left heart border is not seen separately. On contrast enhanced CT scan of the chest, there is a well defined non enhancing collection in the left anterior and middle mediastinum.