MRCP2-4351
A 68-year-old man presents to the outpatient department with a history of cough and dyspnoea for the past four months. He experiences coughing most mornings and brings up mucoid sputum. He denies any haemoptysis but has become increasingly breathless on exertion, limiting his exercise tolerance to 100 metres on the flat. He reports constant pain in his right shoulder that has started to keep him awake at night over the last couple of months, as well as pain in the medial aspect of his right arm. He has a reduced appetite and has lost 5 kg in weight. He has a forty pack year smoking history and is a retired engineer. He has signs of rheumatoid arthritis in his hands, with bilateral finger clubbing and wasting of small muscles in his right hand, particularly the thenar and hypothenar eminences.
What is the preferred diagnostic test for this patient?