[A case of inflammatory pseudotumor of the lung that extended to involve the mediastinum].

A 17-year-old woman was referred to our hospital because of cough and fever. The chest X-ray films revealed an anterior mediastinal mass shadow. Steroid drugs and antibiotics were administered and the shadow diminished slightly. To confirm diagnosis, open thoracotomy was performed. The tumor was extended to the mediastinum, thymus and heart as well as the right middle lobe and right lower lobe. Microscopic findings of the resected tumor showed proliferation of histiocytes with infiltration by inflammatory cells, lymphocytes and fibrous tissue.