A 40 year old man presents with progressively worsening exertional dyspnea for 6 months. He is otherwise asymptomatic.

He gives a history of blunt abdominal trauma following a motor vehicle accident 4 years ago. An emergency laparotomy was performed, during which a laceration of the liver was detected. His medical history is otherwise unremarkable.

He does not smoke and there is no family history of malignancies or cardiac or respiratory diseases.