[A case of eosinophilic granuloma associated with a brain lesion].

A 32-year-old man was hospitalized due to right pneumothorax. Chest X-ray showed interstitial shadows predominantly in the upper and middle lung fields. Eosinophilic granuloma was diagnosed by transbronchial lung biopsy. He had a history of paraesthesia in the right arm for 6 months prior to the pneumothorax. Initially, head CT showed an iso-dense area enhanced with contrast medium in the left temporal lobe. Two weeks after the onset of paraesthesia, head CT showed an iso-dense lesion surrounded by low density area. Subjective symptoms disappeared in a month, and no abnormalities on head CT were seen at 2 months. It is highly suspected; therefore, that the present case of eosinophilic granuloma was associated with a brain lesion.