Pulmonary cyst newly formed after lobectomy in various underlying lung conditions.

Background: It has been recently recognized that pulmonary cyst may develop after pulmonary resection, causing various symptoms. Most previously reported cases were after upper lobectomy in patients with chronic obstructive lung disease (COPD).

Case Presentation: Case 1 was a man in his 70 s with interstitial pneumonia (IP). Right lower lobectomy was performed for metastatic lung tumor using video-assisted thoracoscopic surgery (VATS). On postoperative day (POD) 19, computed tomography (CT) revealed a large cyst at the upper interlobular surface of the middle lobe, with pneumoderma and pneumomediastinum. The cyst was incised, polyglycolic acid (PGA) sheet and fibrin glue were applied, and the cyst was sutured. The sutured line was covered again with PGA sheet and fibrin glue. Case 2 was a man in his 70 s with COPD. Right upper lobectomy for primary lung cancer was performed using VATS. On POD 17, CT revealed a large pulmonary cyst at the apex of S6 and massive air leakage was observed. The same surgical procedure as that used in case 1 was performed. Cases 3 and 4 were healthy donors for living-donor lung transplantation. Two months after the right lower lobectomy in Case 3 and 3 months after the left lower lobectomy in Case 4, the patients had respiratory symptoms such as dyspnea and hemosputum. CT revealed a large cyst on the diaphragmatic surface of the right middle lobe in Case 3 and on the posterior mediastinal surface of the left upper lobe in Case 4. Cyst incision, soft coagulation, and application of PGA sheet with fibrin glue were performed in both cases. CT performed 1 year after surgery showed no development of a pulmonary cyst or air space in these four cases.

Conclusions: Pulmonary cysts newly formed after lobectomy can develop not only in COPD or IP but also in healthy lungs. Our findings suggest that incision of the cyst and application of fibrin glue and PGA sheet with or without suturing the cyst wall is effective for management.