CEACAM5 and neoplasm: However, CEA, as one of tumor markers, presents to be available for assisting in lung cancer diagnosis, especially for non-small-cell lung cancer, while the specificity of CEA is not high.<h4>Methods</h4>Here, we described a case of bronchial opening obstruction with elevated carcinoembryonic antigen (CEA) that was firstly misdiagnosed as lung cancer and proved as foreign body aspiration in the upper lobe bronchus of right lung by bronchoscopy.<h4>Results</h4>Carcinoembryonic antigen level increased.