A case of mesenchymal cystic hamartoma of the lung

Abstract

A 47-year-old woman was admitted due to a right pneumothorax. Chest CT showed a large cystic lesion in the middle lobe of the right lung. Because of prolonged air leakage, surgery was performed. The cyst occupied almost all of the middle lobe, and right middle lobe resection was performed. Pathologically, the inner surface of the cyst was covered with ciliated epithelium, and components of cartilage and smooth muscle were found in the cyst wall. Thus, it was diagnosed as mesenchymal cystic hamartoma. Mesenchymal cystic hamartoma of the lung is rare, but it should be considered as a differential diagnosis of cystic lung disease.