Restrictive lung diseases Quiz: Ace Your Exams

A 57-year-old woman presents to her primary care physician with progressive shortness of breath. She reports an insidious onset of symptoms over the past several weeks and reports she can no longer climb a flight of stairs without “huffing and puffing for air.” She recently completed doxorubicin chemotherapy for breast cancer. Her other past medical history includes hypertension, atrial fibrillation, and hyperlipidemia. Her daily medications include losartan, amiodarone, and simvastatin. She does not smoke or use illicit substances. Vitals are within normal limits. Her physical examination is notable for diffuse bilateral rales more prominent at the lung bases. She subsequently undergoes pulmonary function testing that demonstrates an increased FEV1/FVC ratio. Which of the following is the most likely etiology of this patient’s clinical presentation?