Two cases of lung herniation treated by surgery or observation.

Lung herniation is rare. We describe two cases; one cured by surgery, and the other observed without surgery. A 61-year-old man underwent minimally invasive cardiac surgery for mitral valve plasty. Four weeks postoperatively, chest computed tomography (CT) revealed exacerbating lung herniation and emergency surgery was performed. A 75-year-old man with metastatic tumor underwent partial resection of the left lower lobe through a 10-cm access window. Three months postoperatively, follow-up chest CT revealed prolapse of a small part of the upper lobe at the site of incision. However, he remained asymptomatic and was observed on an outpatient basis.