[Principles of differential diagnosis of diffuse lesions of the lungs].

Intricate questions related to the differential diagnosis of diverse diffuse pulmonary disorders are analysed in more than 1500 patients. Among them 1100 patients had sarcoidosis, 284 alveolitis of different etiology (including 62 patients with fibrotic alveolitis of autoimmune genesis), 45 rare pulmonary diseases, 5 carcinomatosis and 40 disseminated tuberculosis. 70% of the patients were hospitalized for pulmonary tuberculosis. Each disease had its typical diagnostic algorithm. In most cases (86-98%) the diagnosis was morphologically evidenced by intrapulmonary transbronchial biopsy. The cytogram of bronchoalveolar washout was examined. Immunologic methods and immunodiagnosis were used to specify the patients' immune status. Considerable attention was given to external respiratory function. The diagnosis of disseminated tuberculosis was verified by bacteriologic examinations and tuberculin diagnosis.