[Three cases of pulmonary eosinophilic granuloma].

CASE 1. A 55-year-old man was admitted because of an abnormality in chest radiographs. Chest HRCT showed multiple cystic lesions with thick and thin walls, and nodules; and strongly suggested pulmonary eosinophilic granuloma (EG). Open lung biopsy revealed granuloma formation and a fibrotic area consistent with EG. CASE 2. A 28-year-old woman was admitted because of chest pain and dyspnea. Chest radiography revealed bilateral pneumothorax. Chest HRCT showed multiple cystic lesions with thick walls involving the entire lung. As lung biopsy revealed, proliferative lesions and cavitation containing S-100 protein-positive histiocytes, we diagnosed this case as pulmonary EG in the active stage. CASE 3. A 32-year-old woman was admitted because of dyspnea. Chest CT showed bullous changes in the lung. As an open lung biopsy revealed, honeycomb changes with S-100 protein-positive histiocytes, this case was diagnosed as the regressive phase of EG. It is known that the chest radiography and HRCT findings of EG are characteristic and vary with the stage, so a surgical lung biopsy is necessary for diagnosis of EG. It is considered that the prognosis of the active phase of EG involving the entire lung is poor.