Inflammatory pseudotumour of the lung mimicking thymoma.

A 36 year old man presented with chest symptoms had a radiological left upper mediastinal lesion, that was interpreted as an anterior mediastinal tumour, consistent with a thymoma. At operation an inflammatory pseudotumour was found in the left upper lobe of the lung, that was projecting across and in front of the mediastinum. The investigation and surgical management of these tumours are reviewed in the light of the presenting symptoms and radiological imaging.