Mr Lin, a Chinese man aged 38 years, presented for review of a recent chest X-ray. The X-ray was ordered as part of a pre-employment assessment. He was asymptomatic, a nonsmoker and had no significant past medical history. Full blood examination, lipids, glucose and liver and renal function were normal (also ordered as part of the pre-employment assessment). On examination, he looked well, with blood pressure 134/78 mmHg, heart rate 72/min, and chest and cardiovascular examinations normal.