Fig. 4

Histopathological findings (×20, hematoxylin and eosin stain). a A photomicrographic image shows the fistula from the esophagus to the lung, not directly to the bronchus. The inner wall of the fistula (arrow) is covered with esophageal stratified squamous epithelium and bronchial epithelium. There is no evidence of inflammatory change. b This microscopic finding may show the septum between the ordinary lung and the sequestrated lung