Respiratorycommon
A 58-year-old man presents with three weeks of progressive breathlessness and a dull right-sided chest ache. He has smoked 30 cigarettes daily for 35 years and has lost 4 kg over two months without trying. He is afebrile with a respiratory rate of 20/min and oxygen saturation of 94% on room air. The trachea is central, and there is reduced expansion, a stony dull percussion note and absent breath sounds over the right lower zone. Chest x-ray shows a homogeneous opacity occupying the lower third of the right hemithorax with a concave upper border. Which one of the following is the most appropriate next step in investigation?