Worsening dyspnea.

A 62-year-old woman presented with a 2- to 3-week history of fatigue, nonproductive cough, dyspnea on exertion, and intermittent fever/chills. Her medical history was significant for rheumatoid arthritis that had been treated with methotrexate and prednisone for the past 6 years. The patient was currently smoking half a pack a day with a 40-pack year history. The patient was a lifelong resident of Arizona and had previously worked in a stone mine. WHAT IS YOUR DIAGNOSIS? HOW WOULD YOU TREAT THIS PATIENT?