[A case of slowly progressing interstitial pneumonia associated with idiopathic thrombocytopenic purpura].

A 72-year-old man had been taking 10 mg/day of prednisone since idiopathic thrombocytopenic purpura (ITP) was diagnosed when he was 60 years old. An interstitial lung shadow was observed on chest X-ray films when he was about 62 years old, and interstitial pneumonia (IP) (chronic-type), etiology unknown was diagnosed. With the progression of honey-comb shadows on the dorsal side of the lower lung fields, cystic changes on the anterior side of the upper lung fields also became more obvious. Slowly progressing IP associated with ITP is very rare. In addition, the chest CT findings of cystic changes on the dorsal side in the lower lung fields and on the anterior side in the upper lung fields are quite interesting.