A pneumatocele observed in the thoracic cavity after bronchoalveolar lavage

A 76-year-old man was admitted to the respiratory medicine department with 5 days of a non-productive cough and exertional dyspnea. A computed tomography revealed multiple mild patchy consolidations in both lungs (Figure 1). Despite antibiotic therapy, there was poor improvement in laboratory and radiological parameters. A bronchoscopy was performed on day 5. The bronchoscopy was wedged in left B5 and a bronchoalveolar lavage (BAL) was performed. After the BAL, we noticed a fistula in the depth of left B5 and saw a structure like a pleural cavity in the back of the fistula (Figure 2). We diagnosed the patient's condition as pneumatocele (PC). BAL showed 46% lymphocytes and the CD4/8 ratio as 3:7. These findings suggested cryptogenic organizing pneumonia (COP). It took 3 weeks for the PC to improve. Bilateral multiple consolidations improved after the administration of a steroid (PSL 0.5 mg/kg). PCs can occur in infections, chest trauma, barotrauma from mechanical ventilation, and bronchial interventions [1,2]. The mechanism of PC formation is closely related to that of a check valve. The check valve may be composed of exudate from inflammation and the destroyed wall of the respiratory tract [3]. In this case, it was considered that the wedged bronchoscopy and collapsed bronchial wall became the check-valve. PCs can be a severe con- www.jcimcr.org Page 2 Citation: Tanaka S, Kitou R, Komuta K, Tanizaki S, Kanai T, et al. A pneumatocele observed in the thoracic cavity after bronchoalveolar lavage. J Clin Images Med Case Rep. 2021; 2(6): 1412. dition including tension pneumothorax, bronchopleural fistula, and secondary infections [4]. In our case, as we were concerned about new complications due to the PC we did not prescribe a steroid for COP until the PC had improved. To our knowledge, no papers have reported internal observations of PC. We herein report the first case of PC observed in the thoracic cavity after BAL.