Adenocarcinoma masked by re‐expansion pulmonary edema after chest drainage for pneumothorax

Re‐expansion pulmonary edema is a rare complication that may occur after chest drainage performed for pneumothorax. This condition manifests as areas of ground‐glass opacities (GGO) and septal thickening on imaging studies. In the case reported here, chest computed tomography (CT) showed diffuse ground‐glass opacity secondary to ruptured bullae in a patient who underwent chest tube drainage for pneumothorax, suggesting re‐expansion pulmonary edema. Histopathological examination of lung tissue resected from the vicinity of the bullae showed focal adenocarcinoma, which was masked by re‐expansion pulmonary edema on preoperative computed tomography. Right upper lobectomy with mediastinal lymph node dissection was performed on postoperative day 3.