Lung shadows seen on chest imaging but not on bronchoscopy may be due to limited lung lesions that do not involve the bronchioles or break through into the lumen of the tubes.
Common causes of lung shadows include lung tumors, tracheal foreign bodies, lung abscesses, and tuberculosis, etc. The larger the foreign body or the larger the extent of the lesion, the more obvious the shadow.
When no abnormality is seen in bronchoscopy, the possibility of foreign body can be basically ruled out, and the rest of the tumor and infectious lesions should be considered. When the lesion is limited or occupies a position outside the airway and cannot be seen directly by bronchoscopy, further examination measures should be taken to clarify the cause of the disease, which can be CT-guided lung puncture biopsy or bronchoscopic ultrasound-guided needle biopsy to help clarify the nature of the lesion.
If there are lung shadows but no bronchoscopic abnormalities, patients are advised to go to the hospital for further counseling.