[Thoracolithiasis detected during video-assisted thoracoscopic surgery for spontaneous pneumothorax: report of a case].

A 32-year-old male was admitted to our hospital for treatment of right recurrent spontaneous pneumothorax. Chest X-ray showed right pneumothorax but chest X-ray and computed tomography (CT) examinations did not demonstrate intrathoracic abnormal mass shadow or abnormal calcifications. We performed video-assisted thoracoscopic surgery for spontaneous pneumothorax. At surgery, an egg-shaped milky white free mass was found in the thoracic cavity, and easily removed. This substance was hard and smooth on the surface and measured 12 x 9 mm. Histologically this mass was composed of fatty necrosis surrounded by hyalinized connective tissue. These findings led to a diagnosis of thoracolithiasis. Thoracolithiasis without any history of chest trauma or intervention is pathologically rare, with only 15 cases including our case in Japan, having been reported in the literature to date.