Overlooked diagnosis of infected paratracheal air cysts in patients with respiratory symptoms

RATIONALE Infected paratracheal air cysts as the focus of respiratory symptoms can be overlooked in practice because of nonspecific symptoms and physician's scant knowledge for this entity. We report 2 cases of infected paratracheal air cyst diagnosed at chest computed tomography (CT) and bronchoscopy/endobronchial ultrasound. PATIENT CONCERN Two patients visited our hospital with respiratory symptoms, including cough, sputum, and fever. DIAGNOSES Chest CT showed paratracheal cystic lesions with air-fluid level in the thoracic inlet. In the first patient, endobronchial ultrasound revealed a right paratracheal hypoechoic mass corresponding to the lesion on CT scan. In the second patient, bronchoscopy revealed purulent discharge from a dimpling at posterolateral wall of trachea, which was the opening of communication between the trachea and infected paratracheal air cyst. INTERVENTIONS Both patients received antibiotic treatment. OUTCOME After medical treatment, the patients' symptoms were improved. Follow-up chest CT scans showed air-filled paratracheal air cysts without internal fluid or rim enhancement. LESSONS A physician should pay attention to paratracheal air cyst in patients with respiratory symptoms when their lungs are clear on CT scan.