A 58-year-old woman with long-standing rheumatoid arthritis on methotrexate and adalimumab presents with a 3-week history of productive cough, night sweats, and a 4 kg weight loss. Chest CT reveals a right upper lobe cavitary lesion. Her QuantiFERON-TB Gold test is indeterminate. Which is the MOST appropriate next step?

Remaining questions and full explanations are VIP-exclusive.