Spontaneous regression of primary lung cancer arising from an emphysematous bulla.

Bullous emphysema is an important risk factor for lung cancer. Here, we report the case of a 56-year-old man who underwent surgical treatment for primary lung cancer arising from the wall of a bulla. Chest computed tomography (CT) had revealed a nodule arising from the bulla wall. This nodule showed positive uptake of (18)fluorodeoxyglucose (FDG) during positron emission tomography (PET)-CT. However, repeat CT performed after 2 months showed a spontaneous decrease in the tumor size. Exploratory resection revealed non-small cell lung cancer, which was confirmed by the findings of intraoperative frozen-section analysis; therefore, right upper lobectomy and mediastinal lymph node dissection were performed. The postoperative, pathological diagnosis was squamous cell carcinoma arising from the wall of a bulla. From this case, we infer that lung cancer arising from the wall of a bulla may spontaneously regress, and FDG/PET is a useful tool to diagnose lung tumor in patients with pulmonary bullous disease.