[Intrathoracic lipoma of which a pedunculated growth was confirmed by the development of pneumothorax before surgery; report of a case].

The patient was a 47-year-old man who had been found to have an intrathoracic lipoma arising from the left chest wall during a routine physical examination 4 years previously, and had been followed-up. He visited our hospital because of left chest pain. Since the tumor had enlarged, he was scheduled for surgery.