Abstract: Objective To deepen the understanding on the diagnosis of sarcoidosis and to reduce the misdiagnosis.  Methods We analyzed retrospectively data of clinical features,diagnosis approaches and misdiagnosis from 45 patient with sarcoidosis hospitalized in our hospital from 1990 to 2000.  Result Of 45 cases, intrathoracic, systemic and extrathoracic sarcoidosis were 30, 14 and 1, respectively. There were 19 cases in stage 1, 24 cases in stage 2 and 1 case in stage 3. In additional, one case belonged to extrathoracic sarcoidosis. Cough and chest tightness were the most common presentation. The best method for confirmed diagnosis was biopsy by mediastinoscopy，thoracoscopy and operation. The alternative method for confirmed diagnosis was also biopsy with superficial lymph nodes and cutaneous focus. In 35 cases, 18 cases were misdiagnosed as pulmonary tuberculosis, 7 cases as pneumonia, 5 cases as lung cancer,3 cases as lymphoma, one case as eye disease and one case as autoimmune disease. Conclusion The clinical manifestation on sarcoidosis is varied and it is easy to be misdiagnosed. If patient has extrathoracic focus, biopsy of superficial lymph nodes and cutaneous focus are recommended as preferred method. It is difficult to differentiate with tuberculosis, lymphoma and lung cancer. Therapy should be considered carefully before confirmed diagnosis.

Key words: sarcoidosis,pulmonary, sarcoidosis, diagnostic errors