[Clinical study of inflammatory diseases, which are difficult to differentiate from tumorous lesions].

Fourteen inflammatory disease cases in which differential diagnoses from tumorous lesions had been difficult and which were confirmed by thoracotomies, were studied. They included 4 plasma cell granulomas, 3 pulmonary abscesses, 2 fungal diseases, and one case of pseudolymphoma, lymphocytic interstitial pneumonia, Wegener's granulomatosis, round atelectasis, organized pneumonia, respectively. In some cases with plasma cell granuloma, lymphoproliferative disease, Wegener's granulomatosis and round atelectasis, it might be possible to correctly diagnose the cases preoperatively, on chest X-ray, clinical symptoms and blood examinations. However in cases with plasma cell granuloma in aged patients, fungal disease, pulmonary abscess and organized pneumonia, there were few characteristic findings for differentiation from benign or malignant tumors. Therefore open thoracotomy will be inevitable for correct diagnosis.