Rapid development and rupture of a pneumatocele caused by pulmonary dissection in the early postoperative period of lung resection: a case report

Air leakage after lung resection is a common complication usually caused by direct injury to the lung parenchyma. Herein we illustrate a case of pneumatocele that developed rapidly in the right middle lobe and ruptured 16 days after right upper lobectomy. A 73-year-old man with chronic obstructive pulmonary disease underwent thoracoscopic right upper lobectomy and partial thymectomy for primary lung cancer and thymic nodules, respectively. Although a small amount of air leakage was observed after the operation, air leakage completely improved on postoperative day (POD) 2, and the chest drain tube was removed on POD 3. The patient's condition was complicated with eosinophilic pneumonia. Steroid therapy was started on POD 13. Dyspnea suddenly developed immediately after defecation on POD 16. Computed tomography (CT) scan showed a large pneumatocele in the right middle lobe, which was not found by CT scan on POD 11. He underwent reoperation on POD 20, and a large thick-walled pneumatocele in the right middle lobe was directly sewn. Histopathologically, the wall of bulla consisted of thickened visceral pleura and thin lung parenchyma, suggesting that this pneumatocele was induced by dissection of subpleural lung parenchyma.