Abstract: Objective: To explore the clinical characteristics,diagnosis and treatment methods of pulomnary sarcoidosis,and to improve the clinicians' understanding of pulmonary sarcoidosis. Methods: The clinical materials,the results of bronchoscope and pathological examinations of one pulomnary sarcoidosis patient were collected,and the relative literatures were reviewed. Results: A patient with cough and progressive dyspnea for 2 months was admitted to the hospital,and the patient had no obvious positive signs. The chest CT images showed diffuse nodules in both lungs, bilateral hilar and mediastinal lymph node enlargement; lung cancer with pulmonary lymphangitic carcinomatosis(PLC),and metastasis of bilateral supraclavicular, bilateral hilar, mediastinal lymph nodes were diagnosed by PET-CT images.The pathological results of fiberoptic bronchoscope after hospitalization showed a chronic granulomatous inflammation in the lung tissue,without obvious necrosis, and tuberculosis could not be entirely excluded.The patients were given glucocorticoids and preventive anti-tuberculosis drugs; 1 month later, the chest CT showed a significant reduction in the bilateral pulmonary nodules; 3 months later, the symptoms of patient disappeared;the chest CT showed the biateral pulmonary nodules basically disappeared,the bilateral hilar and mediastinal lymph nodes were markedly shrunk;the pulmonary sarcoidosis was diagnosed finally. Conclusion: The diagnosis of pulomnary sarcoidosis should be mainly based on the pathological diagnosis combined with clinical manifestation of the patient;sarcoidosis is easily misdiagnosed as tumor or tuberculosis only by the clinical manifestations and the imaging results.

Key words: sarcoidosis, pulomnary sarcoidosis, case reports, pulmonary lymphangitic carcinomatosis