[A case of cryptogenic organizing pneumonia with eosinophilic infiltration which was difficult to distinguish from nonspecific interstitial pneumonia].

A 57-year-old man presented with shortness of breath of four months duration which had recently become worse. A chest X-ray and computed tomography (CT) showed diffuse ground-glass opacities of the bilateral lower lungs suggesting interstitial pneumonia. The number of eosinophils was increased in the bronchoalveolar lavage fluid (BALF) (52%) and peripheral blood. A histological examination of the specimen obtained by TBLB revealed organized pneumonia with slight infiltration of inflammatory cell. Because the images were not typical of chronic eosinophilic pneumonia, video-assisted thoracic surgery biopsy was performed. The histological findings of the resected specimen showed organizing pneumonia with infiltration of eosinophils in the alveolar walls. He had not taken any medication prior to coming to the hospital and he was negative for medicine-related pneumonia. The oral administration of prednisolone (0.5 mg/kg) improved his symptoms and also CT findings.